gpu/command_buffer/service/gles2_cmd

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This source file includes following definitions.
CityHashForAngle
PrecisionMeetsSpecForHighpFloat
GetShaderPrecisionFormatImpl
AddressAfterStruct
GetImmediateDataAs
ComputeDataSize
CharacterIsValidForGLES
StringIsValidForGLES
EnableDisable
id
size
id
id
DidComplete
GetServiceTextureId
log_commands_
BeginDecoding
EndDecoding
GetGLES2Util
GetGLContext
GetContextGroup
RestoreActiveTexture
RestoreAllTextureUnitBindings
RestoreActiveTextureUnitBinding
RestoreAttribute
RestoreBufferBindings
RestoreGlobalState
RestoreProgramBindings
RestoreTextureUnitBindings
GetQueryManager
GetVertexArrayManager
GetContextState
buffer_manager
renderbuffer_manager
framebuffer_manager
program_manager
shader_manager
shader_translator_cache
texture_manager
texture_manager
mailbox_manager
image_manager
vertex_array_manager
memory_tracker
EnsureGPUMemoryAvailable
IsOffscreenBufferMultisampled
CreateTexture
GetTexture
RemoveTexture
CreateProgram
GetProgram
LogClientServiceMapping
LogClientServiceForInfo
LogClientServiceMapping
LogClientServiceForInfo
GetProgramInfoNotShader
CreateShader
GetShader
GetShaderInfoNotProgram
CreateBuffer
GetBuffer
CreateFramebuffer
GetFramebuffer
RemoveFramebuffer
CreateRenderbuffer
GetRenderbuffer
RemoveRenderbuffer
GetVertexAttribManager
RemoveVertexAttribManager
CreateVertexAttribManager
DoReleaseShaderCompiler
GetBindTargetForSamplerType
GetFramebufferInfoForTarget
GetRenderbufferInfoForTarget
features
workarounds
ShouldDeferDraws
ShouldDeferReads
WillAccessBoundFramebufferForDraw
WillAccessBoundFramebufferForRead
error_state_
RestoreCurrentTextureBindings
target_
id_
Create
AllocateStorage
Copy
Destroy
Invalidate
id_
Create
AllocateStorage
Destroy
Invalidate
id_
Create
AttachRenderTexture
AttachRenderBuffer
Destroy
Invalidate
CheckStatus
Create
validation_fbo_
Initialize
GetCapabilities
UpdateCapabilities
InitializeShaderTranslator
GenBuffersHelper
GenFramebuffersHelper
GenRenderbuffersHelper
GenTexturesHelper
DeleteBuffersHelper
DeleteFramebuffersHelper
DeleteRenderbuffersHelper
DeleteTexturesHelper
MakeCurrent
ProcessFinishedAsyncTransfers
RebindCurrentFramebuffer
RestoreCurrentFramebufferBindings
CheckFramebufferValid
CheckBoundFramebuffersValid
GetBoundReadFrameBufferSize
GetBoundReadFrameBufferTextureType
GetBoundReadFrameBufferInternalFormat
GetBoundDrawFrameBufferInternalFormat
UpdateParentTextureInfo
SetResizeCallback
GetLogger
BeginDecoding
EndDecoding
GetErrorState
SetShaderCacheCallback
SetWaitSyncPointCallback
GetAsyncPixelTransferManager
ResetAsyncPixelTransferManagerForTest
SetAsyncPixelTransferManagerForTest
GetServiceTextureId
GetTextureUploadCount
GetTotalTextureUploadTime
GetTotalProcessingCommandsTime
AddProcessingCommandsTime
Destroy
SetSurface
ProduceFrontBuffer
ResizeOffscreenFrameBuffer
HandleResizeCHROMIUM
GetCommandName
DoCommand
RemoveBuffer
CreateProgramHelper
CreateShaderHelper
DoFinish
DoFlush
DoActiveTexture
DoBindBuffer
BoundFramebufferHasColorAttachmentWithAlpha
BoundFramebufferHasDepthAttachment
BoundFramebufferHasStencilAttachment
ApplyDirtyState
GetBackbufferServiceId
RestoreState
RestoreFramebufferBindings
RestoreTextureState
ClearAllAttributes
RestoreAllAttributes
OnFboChanged
OnUseFramebuffer
DoBindFramebuffer
DoBindRenderbuffer
DoBindTexture
DoDisableVertexAttribArray
DoDiscardFramebufferEXT
DoEnableVertexAttribArray
DoGenerateMipmap
GetHelper
GetNumValuesReturnedForGLGet
AdjustGetPname
DoGetBooleanv
DoGetFloatv
DoGetIntegerv
DoGetProgramiv
DoGetBufferParameteriv
DoBindAttribLocation
HandleBindAttribLocation
HandleBindAttribLocationBucket
DoBindUniformLocationCHROMIUM
HandleBindUniformLocationCHROMIUM
HandleBindUniformLocationCHROMIUMBucket
HandleDeleteShader
HandleDeleteProgram
DoDeleteSharedIdsCHROMIUM
HandleDeleteSharedIdsCHROMIUM
DoGenSharedIdsCHROMIUM
HandleGenSharedIdsCHROMIUM
DoRegisterSharedIdsCHROMIUM
HandleRegisterSharedIdsCHROMIUM
DoClear
DoFramebufferRenderbuffer
DoDisable
DoEnable
DoDepthRangef
DoSampleCoverage
ClearUnclearedAttachments
RestoreClearState
DoCheckFramebufferStatus
DoFramebufferTexture2D
DoFramebufferTexture2DMultisample
DoFramebufferTexture2DCommon
DoGetFramebufferAttachmentParameteriv
DoGetRenderbufferParameteriv
DoBlitFramebufferCHROMIUM
RenderbufferStorageMultisampleHelper
BlitFramebufferHelper
ValidateRenderbufferStorageMultisample
DoRenderbufferStorageMultisampleCHROMIUM
DoRenderbufferStorageMultisampleEXT
VerifyMultisampleRenderbufferIntegrity
DoRenderbufferStorage
DoLinkProgram
DoTexParameterf
DoTexParameteri
DoTexParameterfv
DoTexParameteriv
CheckCurrentProgram
CheckCurrentProgramForUniform
PrepForSetUniformByLocation
DoUniform1i
DoUniform1iv
DoUniform1fv
DoUniform2fv
DoUniform3fv
DoUniform4fv
DoUniform2iv
DoUniform3iv
DoUniform4iv
DoUniformMatrix2fv
DoUniformMatrix3fv
DoUniformMatrix4fv
DoUseProgram
RenderWarning
PerformanceWarning
DoWillUseTexImageIfNeeded
DoDidUseTexImageIfNeeded
PrepareTexturesForRender
RestoreStateForTextures
ClearUnclearedTextures
IsDrawValid
SimulateAttrib0
RestoreStateForAttrib
SimulateFixedAttribs
RestoreStateForSimulatedFixedAttribs
DoDrawArrays
HandleDrawArrays
HandleDrawArraysInstancedANGLE
DoDrawElements
HandleDrawElements
HandleDrawElementsInstancedANGLE
DoGetMaxValueInBufferCHROMIUM
ShaderSourceHelper
HandleShaderSource
HandleShaderSourceBucket
DoCompileShader
DoGetShaderiv
HandleGetShaderSource
HandleGetTranslatedShaderSourceANGLE
HandleGetProgramInfoLog
HandleGetShaderInfoLog
DoIsEnabled
DoIsBuffer
DoIsFramebuffer
DoIsProgram
DoIsRenderbuffer
DoIsShader
DoIsTexture
DoAttachShader
DoDetachShader
DoValidateProgram
GetVertexAttribHelper
DoGetTexParameterfv
DoGetTexParameteriv
InitTextureMaxAnisotropyIfNeeded
DoGetVertexAttribfv
DoGetVertexAttribiv
SetVertexAttribValue
DoVertexAttrib1f
DoVertexAttrib2f
DoVertexAttrib3f
DoVertexAttrib4f
DoVertexAttrib1fv
DoVertexAttrib2fv
DoVertexAttrib3fv
DoVertexAttrib4fv
HandleVertexAttribPointer
DoViewport
HandleVertexAttribDivisorANGLE
WriteAlphaData
FinishReadPixels
HandleReadPixels
HandlePixelStorei
HandlePostSubBufferCHROMIUM
GetAttribLocationHelper
HandleGetAttribLocation
HandleGetAttribLocationBucket
GetUniformLocationHelper
HandleGetUniformLocation
HandleGetUniformLocationBucket
HandleGetString
HandleBufferData
DoBufferSubData
ClearLevel
IsValidDXTSize
ValidateCompressedTexFuncData
ValidateCompressedTexDimensions
ValidateCompressedTexSubDimensions
DoCompressedTexImage2D
HandleCompressedTexImage2D
HandleCompressedTexImage2DBucket
HandleCompressedTexSubImage2DBucket
HandleTexImage2D
DoCompressedTexSubImage2D
Clip
DoCopyTexImage2D
DoCopyTexSubImage2D
ValidateTexSubImage2D
DoTexSubImage2D
HandleTexSubImage2D
HandleGetVertexAttribPointerv
GetUniformSetup
HandleGetUniformiv
HandleGetUniformfv
HandleGetShaderPrecisionFormat
HandleGetAttachedShaders
HandleGetActiveUniform
HandleGetActiveAttrib
HandleShaderBinary
DoSwapBuffers
HandleEnableFeatureCHROMIUM
HandleGetRequestableExtensionsCHROMIUM
HandleRequestExtensionCHROMIUM
HandleGetMultipleIntegervCHROMIUM
HandleGetProgramInfoCHROMIUM
GetContextLostReason
WasContextLost
WasContextLostByRobustnessExtension
LoseContext
HandleLoseContextCHROMIUM
HandleInsertSyncPointCHROMIUM
HandleWaitSyncPointCHROMIUM
HandleDiscardBackbufferCHROMIUM
GenQueriesEXTHelper
DeleteQueriesEXTHelper
ProcessPendingQueries
WaitForReadPixels
ProcessPendingReadPixels
HasMoreIdleWork
PerformIdleWork
HandleBeginQueryEXT
HandleEndQueryEXT
GenVertexArraysOESHelper
DeleteVertexArraysOESHelper
DoBindVertexArrayOES
EmulateVertexArrayState
DoIsVertexArrayOES
ReleaseIOSurfaceForTexture
DoTexImageIOSurface2DCHROMIUM
ExtractFormatFromStorageFormat
DoCopyTextureCHROMIUM
ExtractTypeFromStorageFormat
DoTexStorage2DEXT
HandleGenMailboxCHROMIUM
DoProduceTextureCHROMIUM
DoConsumeTextureCHROMIUM
DoInsertEventMarkerEXT
DoPushGroupMarkerEXT
DoPopGroupMarkerEXT
DoBindTexImage2DCHROMIUM
DoReleaseTexImage2DCHROMIUM
HandleTraceBeginCHROMIUM
DoTraceEndCHROMIUM
DoDrawBuffersEXT
ValidateAsyncTransfer
AsyncUploadTokenCompletionClosure
HandleAsyncTexImage2DCHROMIUM
HandleAsyncTexSubImage2DCHROMIUM
HandleWaitAsyncTexImage2DCHROMIUM
HandleWaitAllAsyncTexImage2DCHROMIUM
OnTextureRefDetachedFromFramebuffer
OnOutOfMemoryError
// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "gpu/command_buffer/service/gles2_cmd_decoder.h"

#include <stdio.h>

#include <algorithm>
#include <list>
#include <map>
#include <stack>
#include <string>
#include <vector>

#include "base/at_exit.h"
#include "base/bind.h"
#include "base/callback_helpers.h"
#include "base/command_line.h"
#include "base/debug/trace_event.h"
#include "base/debug/trace_event_synthetic_delay.h"
#include "base/memory/scoped_ptr.h"
#include "base/numerics/safe_math.h"
#include "base/strings/string_number_conversions.h"
#include "base/strings/string_split.h"
#include "build/build_config.h"
#define GLES2_GPU_SERVICE 1
#include "gpu/command_buffer/common/debug_marker_manager.h"
#include "gpu/command_buffer/common/gles2_cmd_format.h"
#include "gpu/command_buffer/common/gles2_cmd_utils.h"
#include "gpu/command_buffer/common/id_allocator.h"
#include "gpu/command_buffer/common/mailbox.h"
#include "gpu/command_buffer/service/async_pixel_transfer_delegate.h"
#include "gpu/command_buffer/service/async_pixel_transfer_manager.h"
#include "gpu/command_buffer/service/buffer_manager.h"
#include "gpu/command_buffer/service/cmd_buffer_engine.h"
#include "gpu/command_buffer/service/context_group.h"
#include "gpu/command_buffer/service/context_state.h"
#include "gpu/command_buffer/service/error_state.h"
#include "gpu/command_buffer/service/feature_info.h"
#include "gpu/command_buffer/service/framebuffer_manager.h"
#include "gpu/command_buffer/service/gl_utils.h"
#include "gpu/command_buffer/service/gles2_cmd_copy_texture_chromium.h"
#include "gpu/command_buffer/service/gles2_cmd_validation.h"
#include "gpu/command_buffer/service/gpu_state_tracer.h"
#include "gpu/command_buffer/service/gpu_switches.h"
#include "gpu/command_buffer/service/gpu_tracer.h"
#include "gpu/command_buffer/service/image_manager.h"
#include "gpu/command_buffer/service/mailbox_manager.h"
#include "gpu/command_buffer/service/memory_tracking.h"
#include "gpu/command_buffer/service/program_manager.h"
#include "gpu/command_buffer/service/query_manager.h"
#include "gpu/command_buffer/service/renderbuffer_manager.h"
#include "gpu/command_buffer/service/shader_manager.h"
#include "gpu/command_buffer/service/shader_translator.h"
#include "gpu/command_buffer/service/shader_translator_cache.h"
#include "gpu/command_buffer/service/texture_manager.h"
#include "gpu/command_buffer/service/vertex_array_manager.h"
#include "gpu/command_buffer/service/vertex_attrib_manager.h"
#include "ui/gl/gl_bindings.h"
#include "ui/gl/gl_fence.h"
#include "ui/gl/gl_image.h"
#include "ui/gl/gl_implementation.h"
#include "ui/gl/gl_surface.h"

#if defined(OS_MACOSX)
#include "ui/gl/io_surface_support_mac.h"
#endif

#if defined(OS_WIN)
#include "base/win/win_util.h"
#endif

// TODO(zmo): we can't include "City.h" due to type def conflicts.
extern uint64 CityHash64(const char*, size_t);

namespace gpu {
namespace gles2 {

namespace {

static const char kOESDerivativeExtension[] = "GL_OES_standard_derivatives";
static const char kEXTFragDepthExtension[] = "GL_EXT_frag_depth";
static const char kEXTDrawBuffersExtension[] = "GL_EXT_draw_buffers";

#if !defined(ANGLE_SH_VERSION) || ANGLE_SH_VERSION < 108
khronos_uint64_t CityHashForAngle(const char* name, unsigned int len) {
  return static_cast<khronos_uint64_t>(
      CityHash64(name, static_cast<size_t>(len)));
}
#endif

static bool PrecisionMeetsSpecForHighpFloat(GLint rangeMin,
                                            GLint rangeMax,
                                            GLint precision) {
  return (rangeMin >= 62) && (rangeMax >= 62) && (precision >= 16);
}

static void GetShaderPrecisionFormatImpl(GLenum shader_type,
                                         GLenum precision_type,
                                         GLint *range, GLint *precision) {
  switch (precision_type) {
    case GL_LOW_INT:
    case GL_MEDIUM_INT:
    case GL_HIGH_INT:
      // These values are for a 32-bit twos-complement integer format.
      range[0] = 31;
      range[1] = 30;
      *precision = 0;
      break;
    case GL_LOW_FLOAT:
    case GL_MEDIUM_FLOAT:
    case GL_HIGH_FLOAT:
      // These values are for an IEEE single-precision floating-point format.
      range[0] = 127;
      range[1] = 127;
      *precision = 23;
      break;
    default:
      NOTREACHED();
      break;
  }

  if (gfx::GetGLImplementation() == gfx::kGLImplementationEGLGLES2 &&
      gfx::g_driver_gl.fn.glGetShaderPrecisionFormatFn) {
    // This function is sometimes defined even though it's really just
    // a stub, so we need to set range and precision as if it weren't
    // defined before calling it.
    // On Mac OS with some GPUs, calling this generates a
    // GL_INVALID_OPERATION error. Avoid calling it on non-GLES2
    // platforms.
    glGetShaderPrecisionFormat(shader_type, precision_type,
                               range, precision);

    // TODO(brianderson): Make the following official workarounds.

    // Some drivers have bugs where they report the ranges as a negative number.
    // Taking the absolute value here shouldn't hurt because negative numbers
    // aren't expected anyway.
    range[0] = abs(range[0]);
    range[1] = abs(range[1]);

    // If the driver reports a precision for highp float that isn't actually
    // highp, don't pretend like it's supported because shader compilation will
    // fail anyway.
    if (precision_type == GL_HIGH_FLOAT &&
        !PrecisionMeetsSpecForHighpFloat(range[0], range[1], *precision)) {
      range[0] = 0;
      range[1] = 0;
      *precision = 0;
    }
  }
}

}  // namespace

class GLES2DecoderImpl;

// Local versions of the SET_GL_ERROR macros
#define LOCAL_SET_GL_ERROR(error, function_name, msg) \
    ERRORSTATE_SET_GL_ERROR(state_.GetErrorState(), error, function_name, msg)
#define LOCAL_SET_GL_ERROR_INVALID_ENUM(function_name, value, label) \
    ERRORSTATE_SET_GL_ERROR_INVALID_ENUM(state_.GetErrorState(), \
                                         function_name, value, label)
#define LOCAL_SET_GL_ERROR_INVALID_PARAM(error, function_name, pname) \
    ERRORSTATE_SET_GL_ERROR_INVALID_PARAM(state_.GetErrorState(), error, \
                                          function_name, pname)
#define LOCAL_COPY_REAL_GL_ERRORS_TO_WRAPPER(function_name) \
    ERRORSTATE_COPY_REAL_GL_ERRORS_TO_WRAPPER(state_.GetErrorState(), \
                                              function_name)
#define LOCAL_PEEK_GL_ERROR(function_name) \
    ERRORSTATE_PEEK_GL_ERROR(state_.GetErrorState(), function_name)
#define LOCAL_CLEAR_REAL_GL_ERRORS(function_name) \
    ERRORSTATE_CLEAR_REAL_GL_ERRORS(state_.GetErrorState(), function_name)
#define LOCAL_PERFORMANCE_WARNING(msg) \
    PerformanceWarning(__FILE__, __LINE__, msg)
#define LOCAL_RENDER_WARNING(msg) \
    RenderWarning(__FILE__, __LINE__, msg)

// Check that certain assumptions the code makes are true. There are places in
// the code where shared memory is passed direclty to GL. Example, glUniformiv,
// glShaderSource. The command buffer code assumes GLint and GLsizei (and maybe
// a few others) are 32bits. If they are not 32bits the code will have to change
// to call those GL functions with service side memory and then copy the results
// to shared memory, converting the sizes.
COMPILE_ASSERT(sizeof(GLint) == sizeof(uint32),  // NOLINT
               GLint_not_same_size_as_uint32);
COMPILE_ASSERT(sizeof(GLsizei) == sizeof(uint32),  // NOLINT
               GLint_not_same_size_as_uint32);
COMPILE_ASSERT(sizeof(GLfloat) == sizeof(float),  // NOLINT
               GLfloat_not_same_size_as_float);

// TODO(kbr): the use of this anonymous namespace core dumps the
// linker on Mac OS X 10.6 when the symbol ordering file is used
// namespace {

// Returns the address of the first byte after a struct.
template <typename T>
const void* AddressAfterStruct(const T& pod) {
  return reinterpret_cast<const uint8*>(&pod) + sizeof(pod);
}

// Returns the address of the frst byte after the struct or NULL if size >
// immediate_data_size.
template <typename RETURN_TYPE, typename COMMAND_TYPE>
RETURN_TYPE GetImmediateDataAs(const COMMAND_TYPE& pod,
                               uint32 size,
                               uint32 immediate_data_size) {
  return (size <= immediate_data_size) ?
      static_cast<RETURN_TYPE>(const_cast<void*>(AddressAfterStruct(pod))) :
      NULL;
}

// Computes the data size for certain gl commands like glUniform.
bool ComputeDataSize(
    GLuint count,
    size_t size,
    unsigned int elements_per_unit,
    uint32* dst) {
  uint32 value;
  if (!SafeMultiplyUint32(count, size, &value)) {
    return false;
  }
  if (!SafeMultiplyUint32(value, elements_per_unit, &value)) {
    return false;
  }
  *dst = value;
  return true;
}

// A struct to hold info about each command.
struct CommandInfo {
  uint8 arg_flags;   // How to handle the arguments for this command
  uint8 cmd_flags;   // How to handle this command
  uint16 arg_count;  // How many arguments are expected for this command.
};

//     cmds::name::cmd_flags,
// A table of CommandInfo for all the commands.
const CommandInfo g_command_info[] = {
  #define GLES2_CMD_OP(name) {                                             \
    cmds::name::kArgFlags,                                                 \
    cmds::name::cmd_flags,                                                 \
    sizeof(cmds::name) / sizeof(CommandBufferEntry) - 1, },  /* NOLINT */

  GLES2_COMMAND_LIST(GLES2_CMD_OP)

  #undef GLES2_CMD_OP
};

// Return true if a character belongs to the ASCII subset as defined in
// GLSL ES 1.0 spec section 3.1.
static bool CharacterIsValidForGLES(unsigned char c) {
  // Printing characters are valid except " $ ` @ \ ' DEL.
  if (c >= 32 && c <= 126 &&
      c != '"' &&
      c != '$' &&
      c != '`' &&
      c != '@' &&
      c != '\\' &&
      c != '\'') {
    return true;
  }
  // Horizontal tab, line feed, vertical tab, form feed, carriage return
  // are also valid.
  if (c >= 9 && c <= 13) {
    return true;
  }

  return false;
}

static bool StringIsValidForGLES(const char* str) {
  for (; *str; ++str) {
    if (!CharacterIsValidForGLES(*str)) {
      return false;
    }
  }
  return true;
}

// Wrapper for glEnable/glDisable that doesn't suck.
static void EnableDisable(GLenum pname, bool enable) {
  if (enable) {
    glEnable(pname);
  } else {
    glDisable(pname);
  }
}

// This class prevents any GL errors that occur when it is in scope from
// being reported to the client.
class ScopedGLErrorSuppressor {
 public:
  explicit ScopedGLErrorSuppressor(
      const char* function_name, ErrorState* error_state);
  ~ScopedGLErrorSuppressor();
 private:
  const char* function_name_;
  ErrorState* error_state_;
  DISALLOW_COPY_AND_ASSIGN(ScopedGLErrorSuppressor);
};

// Temporarily changes a decoder's bound texture and restore it when this
// object goes out of scope. Also temporarily switches to using active texture
// unit zero in case the client has changed that to something invalid.
class ScopedTextureBinder {
 public:
  explicit ScopedTextureBinder(ContextState* state, GLuint id, GLenum target);
  ~ScopedTextureBinder();

 private:
  ContextState* state_;
  GLenum target_;
  DISALLOW_COPY_AND_ASSIGN(ScopedTextureBinder);
};

// Temporarily changes a decoder's bound render buffer and restore it when this
// object goes out of scope.
class ScopedRenderBufferBinder {
 public:
  explicit ScopedRenderBufferBinder(ContextState* state, GLuint id);
  ~ScopedRenderBufferBinder();

 private:
  ContextState* state_;
  DISALLOW_COPY_AND_ASSIGN(ScopedRenderBufferBinder);
};

// Temporarily changes a decoder's bound frame buffer and restore it when this
// object goes out of scope.
class ScopedFrameBufferBinder {
 public:
  explicit ScopedFrameBufferBinder(GLES2DecoderImpl* decoder, GLuint id);
  ~ScopedFrameBufferBinder();

 private:
  GLES2DecoderImpl* decoder_;
  DISALLOW_COPY_AND_ASSIGN(ScopedFrameBufferBinder);
};

// Temporarily changes a decoder's bound frame buffer to a resolved version of
// the multisampled offscreen render buffer if that buffer is multisampled, and,
// if it is bound or enforce_internal_framebuffer is true. If internal is
// true, the resolved framebuffer is not visible to the parent.
class ScopedResolvedFrameBufferBinder {
 public:
  explicit ScopedResolvedFrameBufferBinder(GLES2DecoderImpl* decoder,
                                           bool enforce_internal_framebuffer,
                                           bool internal);
  ~ScopedResolvedFrameBufferBinder();

 private:
  GLES2DecoderImpl* decoder_;
  bool resolve_and_bind_;
  DISALLOW_COPY_AND_ASSIGN(ScopedResolvedFrameBufferBinder);
};

class ScopedModifyPixels {
 public:
  explicit ScopedModifyPixels(TextureRef* ref);
  ~ScopedModifyPixels();

 private:
  TextureRef* ref_;
};

ScopedModifyPixels::ScopedModifyPixels(TextureRef* ref) : ref_(ref) {
  if (ref_)
    ref_->texture()->OnWillModifyPixels();
}

ScopedModifyPixels::~ScopedModifyPixels() {
  if (ref_)
    ref_->texture()->OnDidModifyPixels();
}

class ScopedRenderTo {
 public:
  explicit ScopedRenderTo(Framebuffer* framebuffer);
  ~ScopedRenderTo();

 private:
  const Framebuffer* framebuffer_;
};

ScopedRenderTo::ScopedRenderTo(Framebuffer* framebuffer)
    : framebuffer_(framebuffer) {
  if (framebuffer)
    framebuffer_->OnWillRenderTo();
}

ScopedRenderTo::~ScopedRenderTo() {
  if (framebuffer_)
    framebuffer_->OnDidRenderTo();
}

// Encapsulates an OpenGL texture.
class BackTexture {
 public:
  explicit BackTexture(MemoryTracker* memory_tracker, ContextState* state);
  ~BackTexture();

  // Create a new render texture.
  void Create();

  // Set the initial size and format of a render texture or resize it.
  bool AllocateStorage(const gfx::Size& size, GLenum format, bool zero);

  // Copy the contents of the currently bound frame buffer.
  void Copy(const gfx::Size& size, GLenum format);

  // Destroy the render texture. This must be explicitly called before
  // destroying this object.
  void Destroy();

  // Invalidate the texture. This can be used when a context is lost and it is
  // not possible to make it current in order to free the resource.
  void Invalidate();

  GLuint id() const {
    return id_;
  }

  gfx::Size size() const {
    return size_;
  }

 private:
  MemoryTypeTracker memory_tracker_;
  ContextState* state_;
  size_t bytes_allocated_;
  GLuint id_;
  gfx::Size size_;
  DISALLOW_COPY_AND_ASSIGN(BackTexture);
};

// Encapsulates an OpenGL render buffer of any format.
class BackRenderbuffer {
 public:
  explicit BackRenderbuffer(
      RenderbufferManager* renderbuffer_manager,
      MemoryTracker* memory_tracker,
      ContextState* state);
  ~BackRenderbuffer();

  // Create a new render buffer.
  void Create();

  // Set the initial size and format of a render buffer or resize it.
  bool AllocateStorage(const FeatureInfo* feature_info,
                       const gfx::Size& size,
                       GLenum format,
                       GLsizei samples);

  // Destroy the render buffer. This must be explicitly called before destroying
  // this object.
  void Destroy();

  // Invalidate the render buffer. This can be used when a context is lost and
  // it is not possible to make it current in order to free the resource.
  void Invalidate();

  GLuint id() const {
    return id_;
  }

 private:
  RenderbufferManager* renderbuffer_manager_;
  MemoryTypeTracker memory_tracker_;
  ContextState* state_;
  size_t bytes_allocated_;
  GLuint id_;
  DISALLOW_COPY_AND_ASSIGN(BackRenderbuffer);
};

// Encapsulates an OpenGL frame buffer.
class BackFramebuffer {
 public:
  explicit BackFramebuffer(GLES2DecoderImpl* decoder);
  ~BackFramebuffer();

  // Create a new frame buffer.
  void Create();

  // Attach a color render buffer to a frame buffer.
  void AttachRenderTexture(BackTexture* texture);

  // Attach a render buffer to a frame buffer. Note that this unbinds any
  // currently bound frame buffer.
  void AttachRenderBuffer(GLenum target, BackRenderbuffer* render_buffer);

  // Destroy the frame buffer. This must be explicitly called before destroying
  // this object.
  void Destroy();

  // Invalidate the frame buffer. This can be used when a context is lost and it
  // is not possible to make it current in order to free the resource.
  void Invalidate();

  // See glCheckFramebufferStatusEXT.
  GLenum CheckStatus();

  GLuint id() const {
    return id_;
  }

 private:
  GLES2DecoderImpl* decoder_;
  GLuint id_;
  DISALLOW_COPY_AND_ASSIGN(BackFramebuffer);
};

struct FenceCallback {
  explicit FenceCallback()
      : fence(gfx::GLFence::Create()) {
    DCHECK(fence);
  }
  std::vector<base::Closure> callbacks;
  scoped_ptr<gfx::GLFence> fence;
};

class AsyncUploadTokenCompletionObserver
    : public AsyncPixelTransferCompletionObserver {
 public:
  explicit AsyncUploadTokenCompletionObserver(uint32 async_upload_token)
      : async_upload_token_(async_upload_token) {
  }

  virtual void DidComplete(const AsyncMemoryParams& mem_params) OVERRIDE {
    DCHECK(mem_params.buffer());
    void* data = mem_params.GetDataAddress();
    AsyncUploadSync* sync = static_cast<AsyncUploadSync*>(data);
    sync->SetAsyncUploadToken(async_upload_token_);
  }

 private:
  virtual ~AsyncUploadTokenCompletionObserver() {
  }

  uint32 async_upload_token_;

  DISALLOW_COPY_AND_ASSIGN(AsyncUploadTokenCompletionObserver);
};

// }  // anonymous namespace.

bool GLES2Decoder::GetServiceTextureId(uint32 client_texture_id,
                                       uint32* service_texture_id) {
  return false;
}

GLES2Decoder::GLES2Decoder()
    : initialized_(false),
      debug_(false),
      log_commands_(false) {
}

GLES2Decoder::~GLES2Decoder() {
}

void GLES2Decoder::BeginDecoding() {}

void GLES2Decoder::EndDecoding() {}

// This class implements GLES2Decoder so we don't have to expose all the GLES2
// cmd stuff to outside this class.
class GLES2DecoderImpl : public GLES2Decoder,
                         public FramebufferManager::TextureDetachObserver,
                         public ErrorStateClient {
 public:
  explicit GLES2DecoderImpl(ContextGroup* group);
  virtual ~GLES2DecoderImpl();

  // Overridden from AsyncAPIInterface.
  virtual Error DoCommand(unsigned int command,
                          unsigned int arg_count,
                          const void* args) OVERRIDE;

  // Overridden from AsyncAPIInterface.
  virtual const char* GetCommandName(unsigned int command_id) const OVERRIDE;

  // Overridden from GLES2Decoder.
  virtual bool Initialize(const scoped_refptr<gfx::GLSurface>& surface,
                          const scoped_refptr<gfx::GLContext>& context,
                          bool offscreen,
                          const gfx::Size& size,
                          const DisallowedFeatures& disallowed_features,
                          const std::vector<int32>& attribs) OVERRIDE;
  virtual void Destroy(bool have_context) OVERRIDE;
  virtual void SetSurface(
      const scoped_refptr<gfx::GLSurface>& surface) OVERRIDE;
  virtual void ProduceFrontBuffer(const Mailbox& mailbox) OVERRIDE;
  virtual bool ResizeOffscreenFrameBuffer(const gfx::Size& size) OVERRIDE;
  void UpdateParentTextureInfo();
  virtual bool MakeCurrent() OVERRIDE;
  virtual GLES2Util* GetGLES2Util() OVERRIDE { return &util_; }
  virtual gfx::GLContext* GetGLContext() OVERRIDE { return context_.get(); }
  virtual ContextGroup* GetContextGroup() OVERRIDE { return group_.get(); }
  virtual Capabilities GetCapabilities() OVERRIDE;
  virtual void RestoreState(const ContextState* prev_state) const OVERRIDE;

  virtual void RestoreActiveTexture() const OVERRIDE {
    state_.RestoreActiveTexture();
  }
  virtual void RestoreAllTextureUnitBindings(
      const ContextState* prev_state) const OVERRIDE {
    state_.RestoreAllTextureUnitBindings(prev_state);
  }
  virtual void RestoreActiveTextureUnitBinding(
      unsigned int target) const OVERRIDE {
    state_.RestoreActiveTextureUnitBinding(target);
  }
  virtual void RestoreAttribute(unsigned index) const OVERRIDE {
    state_.RestoreAttribute(index);
  }
  virtual void RestoreBufferBindings() const OVERRIDE {
    state_.RestoreBufferBindings();
  }
  virtual void RestoreGlobalState() const OVERRIDE {
    state_.RestoreGlobalState();
  }
  virtual void RestoreProgramBindings() const OVERRIDE {
    state_.RestoreProgramBindings();
  }
  virtual void RestoreTextureUnitBindings(unsigned unit) const OVERRIDE {
    state_.RestoreTextureUnitBindings(unit, NULL);
  }
  virtual void RestoreFramebufferBindings() const OVERRIDE;
  virtual void RestoreTextureState(unsigned service_id) const OVERRIDE;

  virtual void ClearAllAttributes() const OVERRIDE;
  virtual void RestoreAllAttributes() const OVERRIDE;

  virtual QueryManager* GetQueryManager() OVERRIDE {
    return query_manager_.get();
  }
  virtual VertexArrayManager* GetVertexArrayManager() OVERRIDE {
    return vertex_array_manager_.get();
  }
  virtual bool ProcessPendingQueries() OVERRIDE;
  virtual bool HasMoreIdleWork() OVERRIDE;
  virtual void PerformIdleWork() OVERRIDE;

  virtual void WaitForReadPixels(base::Closure callback) OVERRIDE;

  virtual void SetResizeCallback(
      const base::Callback<void(gfx::Size, float)>& callback) OVERRIDE;

  virtual Logger* GetLogger() OVERRIDE;

  virtual void BeginDecoding() OVERRIDE;
  virtual void EndDecoding() OVERRIDE;

  virtual ErrorState* GetErrorState() OVERRIDE;
  virtual const ContextState* GetContextState() OVERRIDE { return &state_; }

  virtual void SetShaderCacheCallback(
      const ShaderCacheCallback& callback) OVERRIDE;
  virtual void SetWaitSyncPointCallback(
      const WaitSyncPointCallback& callback) OVERRIDE;

  virtual AsyncPixelTransferManager*
      GetAsyncPixelTransferManager() OVERRIDE;
  virtual void ResetAsyncPixelTransferManagerForTest() OVERRIDE;
  virtual void SetAsyncPixelTransferManagerForTest(
      AsyncPixelTransferManager* manager) OVERRIDE;
  void ProcessFinishedAsyncTransfers();

  virtual bool GetServiceTextureId(uint32 client_texture_id,
                                   uint32* service_texture_id) OVERRIDE;

  virtual uint32 GetTextureUploadCount() OVERRIDE;
  virtual base::TimeDelta GetTotalTextureUploadTime() OVERRIDE;
  virtual base::TimeDelta GetTotalProcessingCommandsTime() OVERRIDE;
  virtual void AddProcessingCommandsTime(base::TimeDelta) OVERRIDE;

  // Restores the current state to the user's settings.
  void RestoreCurrentFramebufferBindings();

  // Sets DEPTH_TEST, STENCIL_TEST and color mask for the current framebuffer.
  void ApplyDirtyState();

  // These check the state of the currently bound framebuffer or the
  // backbuffer if no framebuffer is bound.
  // If all_draw_buffers is false, only check with COLOR_ATTACHMENT0, otherwise
  // check with all attached and enabled color attachments.
  bool BoundFramebufferHasColorAttachmentWithAlpha(bool all_draw_buffers);
  bool BoundFramebufferHasDepthAttachment();
  bool BoundFramebufferHasStencilAttachment();

  virtual error::ContextLostReason GetContextLostReason() OVERRIDE;

  // Overridden from FramebufferManager::TextureDetachObserver:
  virtual void OnTextureRefDetachedFromFramebuffer(
      TextureRef* texture) OVERRIDE;

  // Overriden from ErrorStateClient.
  virtual void OnOutOfMemoryError() OVERRIDE;

  // Helpers to facilitate calling into compatible extensions.
  static void RenderbufferStorageMultisampleHelper(
      const FeatureInfo* feature_info,
      GLenum target,
      GLsizei samples,
      GLenum internal_format,
      GLsizei width,
      GLsizei height);

  void BlitFramebufferHelper(GLint srcX0,
                             GLint srcY0,
                             GLint srcX1,
                             GLint srcY1,
                             GLint dstX0,
                             GLint dstY0,
                             GLint dstX1,
                             GLint dstY1,
                             GLbitfield mask,
                             GLenum filter);

 private:
  friend class ScopedFrameBufferBinder;
  friend class ScopedResolvedFrameBufferBinder;
  friend class BackFramebuffer;

  // Initialize or re-initialize the shader translator.
  bool InitializeShaderTranslator();

  void UpdateCapabilities();

  // Helpers for the glGen and glDelete functions.
  bool GenTexturesHelper(GLsizei n, const GLuint* client_ids);
  void DeleteTexturesHelper(GLsizei n, const GLuint* client_ids);
  bool GenBuffersHelper(GLsizei n, const GLuint* client_ids);
  void DeleteBuffersHelper(GLsizei n, const GLuint* client_ids);
  bool GenFramebuffersHelper(GLsizei n, const GLuint* client_ids);
  void DeleteFramebuffersHelper(GLsizei n, const GLuint* client_ids);
  bool GenRenderbuffersHelper(GLsizei n, const GLuint* client_ids);
  void DeleteRenderbuffersHelper(GLsizei n, const GLuint* client_ids);
  bool GenQueriesEXTHelper(GLsizei n, const GLuint* client_ids);
  void DeleteQueriesEXTHelper(GLsizei n, const GLuint* client_ids);
  bool GenVertexArraysOESHelper(GLsizei n, const GLuint* client_ids);
  void DeleteVertexArraysOESHelper(GLsizei n, const GLuint* client_ids);

  // Helper for async upload token completion notification callback.
  base::Closure AsyncUploadTokenCompletionClosure(uint32 async_upload_token,
                                                  uint32 sync_data_shm_id,
                                                  uint32 sync_data_shm_offset);



  // Workarounds
  void OnFboChanged() const;
  void OnUseFramebuffer() const;

  // TODO(gman): Cache these pointers?
  BufferManager* buffer_manager() {
    return group_->buffer_manager();
  }

  RenderbufferManager* renderbuffer_manager() {
    return group_->renderbuffer_manager();
  }

  FramebufferManager* framebuffer_manager() {
    return group_->framebuffer_manager();
  }

  ProgramManager* program_manager() {
    return group_->program_manager();
  }

  ShaderManager* shader_manager() {
    return group_->shader_manager();
  }

  ShaderTranslatorCache* shader_translator_cache() {
    return group_->shader_translator_cache();
  }

  const TextureManager* texture_manager() const {
    return group_->texture_manager();
  }

  TextureManager* texture_manager() {
    return group_->texture_manager();
  }

  MailboxManager* mailbox_manager() {
    return group_->mailbox_manager();
  }

  ImageManager* image_manager() {
    return group_->image_manager();
  }

  VertexArrayManager* vertex_array_manager() {
    return vertex_array_manager_.get();
  }

  MemoryTracker* memory_tracker() {
    return group_->memory_tracker();
  }

  bool EnsureGPUMemoryAvailable(size_t estimated_size) {
    MemoryTracker* tracker = memory_tracker();
    if (tracker) {
      return tracker->EnsureGPUMemoryAvailable(estimated_size);
    }
    return true;
  }

  bool IsOffscreenBufferMultisampled() const {
    return offscreen_target_samples_ > 1;
  }

  // Creates a Texture for the given texture.
  TextureRef* CreateTexture(
      GLuint client_id, GLuint service_id) {
    return texture_manager()->CreateTexture(client_id, service_id);
  }

  // Gets the texture info for the given texture. Returns NULL if none exists.
  TextureRef* GetTexture(GLuint client_id) const {
    return texture_manager()->GetTexture(client_id);
  }

  // Deletes the texture info for the given texture.
  void RemoveTexture(GLuint client_id) {
    texture_manager()->RemoveTexture(client_id);
  }

  // Get the size (in pixels) of the currently bound frame buffer (either FBO
  // or regular back buffer).
  gfx::Size GetBoundReadFrameBufferSize();

  // Get the format of the currently bound frame buffer (either FBO or regular
  // back buffer)
  GLenum GetBoundReadFrameBufferTextureType();
  GLenum GetBoundReadFrameBufferInternalFormat();
  GLenum GetBoundDrawFrameBufferInternalFormat();

  // Wrapper for CompressedTexImage2D commands.
  error::Error DoCompressedTexImage2D(
      GLenum target,
      GLint level,
      GLenum internal_format,
      GLsizei width,
      GLsizei height,
      GLint border,
      GLsizei image_size,
      const void* data);

  // Wrapper for CompressedTexSubImage2D.
  void DoCompressedTexSubImage2D(
      GLenum target,
      GLint level,
      GLint xoffset,
      GLint yoffset,
      GLsizei width,
      GLsizei height,
      GLenum format,
      GLsizei imageSize,
      const void * data);

  // Wrapper for CopyTexImage2D.
  void DoCopyTexImage2D(
      GLenum target,
      GLint level,
      GLenum internal_format,
      GLint x,
      GLint y,
      GLsizei width,
      GLsizei height,
      GLint border);

  // Wrapper for SwapBuffers.
  void DoSwapBuffers();

  // Wrapper for CopyTexSubImage2D.
  void DoCopyTexSubImage2D(
      GLenum target,
      GLint level,
      GLint xoffset,
      GLint yoffset,
      GLint x,
      GLint y,
      GLsizei width,
      GLsizei height);

  // Validation for TexSubImage2D.
  bool ValidateTexSubImage2D(
      error::Error* error,
      const char* function_name,
      GLenum target,
      GLint level,
      GLint xoffset,
      GLint yoffset,
      GLsizei width,
      GLsizei height,
      GLenum format,
      GLenum type,
      const void * data);

  // Wrapper for TexSubImage2D.
  error::Error DoTexSubImage2D(
      GLenum target,
      GLint level,
      GLint xoffset,
      GLint yoffset,
      GLsizei width,
      GLsizei height,
      GLenum format,
      GLenum type,
      const void * data);

  // Extra validation for async tex(Sub)Image2D.
  bool ValidateAsyncTransfer(
      const char* function_name,
      TextureRef* texture_ref,
      GLenum target,
      GLint level,
      const void * data);

  // Wrapper for TexImageIOSurface2DCHROMIUM.
  void DoTexImageIOSurface2DCHROMIUM(
      GLenum target,
      GLsizei width,
      GLsizei height,
      GLuint io_surface_id,
      GLuint plane);

  void DoCopyTextureCHROMIUM(
      GLenum target,
      GLuint source_id,
      GLuint target_id,
      GLint level,
      GLenum internal_format,
      GLenum dest_type);

  // Wrapper for TexStorage2DEXT.
  void DoTexStorage2DEXT(
      GLenum target,
      GLint levels,
      GLenum internal_format,
      GLsizei width,
      GLsizei height);

  void DoProduceTextureCHROMIUM(GLenum target, const GLbyte* key);
  void DoConsumeTextureCHROMIUM(GLenum target, const GLbyte* key);

  void DoBindTexImage2DCHROMIUM(
      GLenum target,
      GLint image_id);
  void DoReleaseTexImage2DCHROMIUM(
      GLenum target,
      GLint image_id);

  void DoTraceEndCHROMIUM(void);

  void DoDrawBuffersEXT(GLsizei count, const GLenum* bufs);

  // Creates a Program for the given program.
  Program* CreateProgram(
      GLuint client_id, GLuint service_id) {
    return program_manager()->CreateProgram(client_id, service_id);
  }

  // Gets the program info for the given program. Returns NULL if none exists.
  Program* GetProgram(GLuint client_id) {
    return program_manager()->GetProgram(client_id);
  }

#if defined(NDEBUG)
  void LogClientServiceMapping(
      const char* /* function_name */,
      GLuint /* client_id */,
      GLuint /* service_id */) {
  }
  template<typename T>
  void LogClientServiceForInfo(
      T* /* info */, GLuint /* client_id */, const char* /* function_name */) {
  }
#else
  void LogClientServiceMapping(
      const char* function_name, GLuint client_id, GLuint service_id) {
    if (service_logging_) {
      VLOG(1) << "[" << logger_.GetLogPrefix() << "] " << function_name
              << ": client_id = " << client_id
              << ", service_id = " << service_id;
    }
  }
  template<typename T>
  void LogClientServiceForInfo(
      T* info, GLuint client_id, const char* function_name) {
    if (info) {
      LogClientServiceMapping(function_name, client_id, info->service_id());
    }
  }
#endif

  // Gets the program info for the given program. If it's not a program
  // generates a GL error. Returns NULL if not program.
  Program* GetProgramInfoNotShader(
      GLuint client_id, const char* function_name) {
    Program* program = GetProgram(client_id);
    if (!program) {
      if (GetShader(client_id)) {
        LOCAL_SET_GL_ERROR(
            GL_INVALID_OPERATION, function_name, "shader passed for program");
      } else {
        LOCAL_SET_GL_ERROR(GL_INVALID_VALUE, function_name, "unknown program");
      }
    }
    LogClientServiceForInfo(program, client_id, function_name);
    return program;
  }


  // Creates a Shader for the given shader.
  Shader* CreateShader(
      GLuint client_id,
      GLuint service_id,
      GLenum shader_type) {
    return shader_manager()->CreateShader(
        client_id, service_id, shader_type);
  }

  // Gets the shader info for the given shader. Returns NULL if none exists.
  Shader* GetShader(GLuint client_id) {
    return shader_manager()->GetShader(client_id);
  }

  // Gets the shader info for the given shader. If it's not a shader generates a
  // GL error. Returns NULL if not shader.
  Shader* GetShaderInfoNotProgram(
      GLuint client_id, const char* function_name) {
    Shader* shader = GetShader(client_id);
    if (!shader) {
      if (GetProgram(client_id)) {
        LOCAL_SET_GL_ERROR(
            GL_INVALID_OPERATION, function_name, "program passed for shader");
      } else {
        LOCAL_SET_GL_ERROR(
            GL_INVALID_VALUE, function_name, "unknown shader");
      }
    }
    LogClientServiceForInfo(shader, client_id, function_name);
    return shader;
  }

  // Creates a buffer info for the given buffer.
  void CreateBuffer(GLuint client_id, GLuint service_id) {
    return buffer_manager()->CreateBuffer(client_id, service_id);
  }

  // Gets the buffer info for the given buffer.
  Buffer* GetBuffer(GLuint client_id) {
    Buffer* buffer = buffer_manager()->GetBuffer(client_id);
    return buffer;
  }

  // Removes any buffers in the VertexAtrribInfos and BufferInfos. This is used
  // on glDeleteBuffers so we can make sure the user does not try to render
  // with deleted buffers.
  void RemoveBuffer(GLuint client_id);

  // Creates a framebuffer info for the given framebuffer.
  void CreateFramebuffer(GLuint client_id, GLuint service_id) {
    return framebuffer_manager()->CreateFramebuffer(client_id, service_id);
  }

  // Gets the framebuffer info for the given framebuffer.
  Framebuffer* GetFramebuffer(GLuint client_id) {
    return framebuffer_manager()->GetFramebuffer(client_id);
  }

  // Removes the framebuffer info for the given framebuffer.
  void RemoveFramebuffer(GLuint client_id) {
    framebuffer_manager()->RemoveFramebuffer(client_id);
  }

  // Creates a renderbuffer info for the given renderbuffer.
  void CreateRenderbuffer(GLuint client_id, GLuint service_id) {
    return renderbuffer_manager()->CreateRenderbuffer(
        client_id, service_id);
  }

  // Gets the renderbuffer info for the given renderbuffer.
  Renderbuffer* GetRenderbuffer(GLuint client_id) {
    return renderbuffer_manager()->GetRenderbuffer(client_id);
  }

  // Removes the renderbuffer info for the given renderbuffer.
  void RemoveRenderbuffer(GLuint client_id) {
    renderbuffer_manager()->RemoveRenderbuffer(client_id);
  }

  // Gets the vertex attrib manager for the given vertex array.
  VertexAttribManager* GetVertexAttribManager(GLuint client_id) {
    VertexAttribManager* info =
        vertex_array_manager()->GetVertexAttribManager(client_id);
    return info;
  }

  // Removes the vertex attrib manager for the given vertex array.
  void RemoveVertexAttribManager(GLuint client_id) {
    vertex_array_manager()->RemoveVertexAttribManager(client_id);
  }

  // Creates a vertex attrib manager for the given vertex array.
  void CreateVertexAttribManager(GLuint client_id, GLuint service_id) {
    return vertex_array_manager()->CreateVertexAttribManager(
      client_id, service_id, group_->max_vertex_attribs());
  }

  void DoBindAttribLocation(GLuint client_id, GLuint index, const char* name);
  void DoBindUniformLocationCHROMIUM(
      GLuint client_id, GLint location, const char* name);

  error::Error GetAttribLocationHelper(
    GLuint client_id, uint32 location_shm_id, uint32 location_shm_offset,
    const std::string& name_str);

  error::Error GetUniformLocationHelper(
    GLuint client_id, uint32 location_shm_id, uint32 location_shm_offset,
    const std::string& name_str);

  // Helper for glShaderSource.
  error::Error ShaderSourceHelper(
      GLuint client_id, const char* data, uint32 data_size);

  // Clear any textures used by the current program.
  bool ClearUnclearedTextures();

  // Clears any uncleared attachments attached to the given frame buffer.
  // Returns false if there was a generated GL error.
  void ClearUnclearedAttachments(GLenum target, Framebuffer* framebuffer);

  // overridden from GLES2Decoder
  virtual bool ClearLevel(unsigned service_id,
                          unsigned bind_target,
                          unsigned target,
                          int level,
                          unsigned internal_format,
                          unsigned format,
                          unsigned type,
                          int width,
                          int height,
                          bool is_texture_immutable) OVERRIDE;

  // Restore all GL state that affects clearing.
  void RestoreClearState();

  // Remembers the state of some capabilities.
  // Returns: true if glEnable/glDisable should actually be called.
  bool SetCapabilityState(GLenum cap, bool enabled);

  // Check that the currently bound framebuffers are valid.
  // Generates GL error if not.
  bool CheckBoundFramebuffersValid(const char* func_name);

  // Check if a framebuffer meets our requirements.
  bool CheckFramebufferValid(
      Framebuffer* framebuffer,
      GLenum target,
      const char* func_name);

  // Checks if the current program exists and is valid. If not generates the
  // appropriate GL error.  Returns true if the current program is in a usable
  // state.
  bool CheckCurrentProgram(const char* function_name);

  // Checks if the current program exists and is valid and that location is not
  // -1. If the current program is not valid generates the appropriate GL
  // error. Returns true if the current program is in a usable state and
  // location is not -1.
  bool CheckCurrentProgramForUniform(GLint location, const char* function_name);

  // Gets the type of a uniform for a location in the current program. Sets GL
  // errors if the current program is not valid. Returns true if the current
  // program is valid and the location exists. Adjusts count so it
  // does not overflow the uniform.
  bool PrepForSetUniformByLocation(GLint fake_location,
                                   const char* function_name,
                                   Program::UniformApiType api_type,
                                   GLint* real_location,
                                   GLenum* type,
                                   GLsizei* count);

  // Gets the service id for any simulated backbuffer fbo.
  GLuint GetBackbufferServiceId() const;

  // Helper for glGetBooleanv, glGetFloatv and glGetIntegerv
  bool GetHelper(GLenum pname, GLint* params, GLsizei* num_written);

  // Helper for glGetVertexAttrib
  void GetVertexAttribHelper(
    const VertexAttrib* attrib, GLenum pname, GLint* param);

  // Wrapper for glCreateProgram
  bool CreateProgramHelper(GLuint client_id);

  // Wrapper for glCreateShader
  bool CreateShaderHelper(GLenum type, GLuint client_id);

  // Wrapper for glActiveTexture
  void DoActiveTexture(GLenum texture_unit);

  // Wrapper for glAttachShader
  void DoAttachShader(GLuint client_program_id, GLint client_shader_id);

  // Wrapper for glBindBuffer since we need to track the current targets.
  void DoBindBuffer(GLenum target, GLuint buffer);

  // Wrapper for glBindFramebuffer since we need to track the current targets.
  void DoBindFramebuffer(GLenum target, GLuint framebuffer);

  // Wrapper for glBindRenderbuffer since we need to track the current targets.
  void DoBindRenderbuffer(GLenum target, GLuint renderbuffer);

  // Wrapper for glBindTexture since we need to track the current targets.
  void DoBindTexture(GLenum target, GLuint texture);

  // Wrapper for glBindVertexArrayOES
  void DoBindVertexArrayOES(GLuint array);
  void EmulateVertexArrayState();

  // Wrapper for glBlitFramebufferCHROMIUM.
  void DoBlitFramebufferCHROMIUM(
      GLint srcX0, GLint srcY0, GLint srcX1, GLint srcY1,
      GLint dstX0, GLint dstY0, GLint dstX1, GLint dstY1,
      GLbitfield mask, GLenum filter);

  // Wrapper for glBufferSubData.
  void DoBufferSubData(
    GLenum target, GLintptr offset, GLsizeiptr size, const GLvoid * data);

  // Wrapper for glCheckFramebufferStatus
  GLenum DoCheckFramebufferStatus(GLenum target);

  // Wrapper for glClear
  error::Error DoClear(GLbitfield mask);

  // Wrappers for various state.
  void DoDepthRangef(GLclampf znear, GLclampf zfar);
  void DoSampleCoverage(GLclampf value, GLboolean invert);

  // Wrapper for glCompileShader.
  void DoCompileShader(GLuint shader);

  // Helper for DeleteSharedIdsCHROMIUM commands.
  void DoDeleteSharedIdsCHROMIUM(
      GLuint namespace_id, GLsizei n, const GLuint* ids);

  // Wrapper for glDetachShader
  void DoDetachShader(GLuint client_program_id, GLint client_shader_id);

  // Wrapper for glDisable
  void DoDisable(GLenum cap);

  // Wrapper for glDisableVertexAttribArray.
  void DoDisableVertexAttribArray(GLuint index);

  // Wrapper for glDiscardFramebufferEXT, since we need to track undefined
  // attachments.
  void DoDiscardFramebufferEXT(GLenum target,
                               GLsizei numAttachments,
                               const GLenum* attachments);

  // Wrapper for glEnable
  void DoEnable(GLenum cap);

  // Wrapper for glEnableVertexAttribArray.
  void DoEnableVertexAttribArray(GLuint index);

  // Wrapper for glFinish.
  void DoFinish();

  // Wrapper for glFlush.
  void DoFlush();

  // Wrapper for glFramebufferRenderbufffer.
  void DoFramebufferRenderbuffer(
      GLenum target, GLenum attachment, GLenum renderbuffertarget,
      GLuint renderbuffer);

  // Wrapper for glFramebufferTexture2D.
  void DoFramebufferTexture2D(
      GLenum target, GLenum attachment, GLenum textarget, GLuint texture,
      GLint level);

  // Wrapper for glFramebufferTexture2DMultisampleEXT.
  void DoFramebufferTexture2DMultisample(
      GLenum target, GLenum attachment, GLenum textarget,
      GLuint texture, GLint level, GLsizei samples);

  // Common implementation for both DoFramebufferTexture2D wrappers.
  void DoFramebufferTexture2DCommon(const char* name,
      GLenum target, GLenum attachment, GLenum textarget,
      GLuint texture, GLint level, GLsizei samples);

  // Wrapper for glGenerateMipmap
  void DoGenerateMipmap(GLenum target);

  // Helper for GenSharedIdsCHROMIUM commands.
  void DoGenSharedIdsCHROMIUM(
      GLuint namespace_id, GLuint id_offset, GLsizei n, GLuint* ids);

  // Helper for DoGetBooleanv, Floatv, and Intergerv to adjust pname
  // to account for different pname values defined in different extension
  // variants.
  GLenum AdjustGetPname(GLenum pname);

  // Wrapper for DoGetBooleanv.
  void DoGetBooleanv(GLenum pname, GLboolean* params);

  // Wrapper for DoGetFloatv.
  void DoGetFloatv(GLenum pname, GLfloat* params);

  // Wrapper for glGetFramebufferAttachmentParameteriv.
  void DoGetFramebufferAttachmentParameteriv(
      GLenum target, GLenum attachment, GLenum pname, GLint* params);

  // Wrapper for glGetIntegerv.
  void DoGetIntegerv(GLenum pname, GLint* params);

  // Gets the max value in a range in a buffer.
  GLuint DoGetMaxValueInBufferCHROMIUM(
      GLuint buffer_id, GLsizei count, GLenum type, GLuint offset);

  // Wrapper for glGetBufferParameteriv.
  void DoGetBufferParameteriv(
      GLenum target, GLenum pname, GLint* params);

  // Wrapper for glGetProgramiv.
  void DoGetProgramiv(
      GLuint program_id, GLenum pname, GLint* params);

  // Wrapper for glRenderbufferParameteriv.
  void DoGetRenderbufferParameteriv(
      GLenum target, GLenum pname, GLint* params);

  // Wrapper for glGetShaderiv
  void DoGetShaderiv(GLuint shader, GLenum pname, GLint* params);

  // Wrappers for glGetTexParameter.
  void DoGetTexParameterfv(GLenum target, GLenum pname, GLfloat* params);
  void DoGetTexParameteriv(GLenum target, GLenum pname, GLint* params);
  void InitTextureMaxAnisotropyIfNeeded(GLenum target, GLenum pname);

  // Wrappers for glGetVertexAttrib.
  void DoGetVertexAttribfv(GLuint index, GLenum pname, GLfloat *params);
  void DoGetVertexAttribiv(GLuint index, GLenum pname, GLint *params);

  // Wrappers for glIsXXX functions.
  bool DoIsEnabled(GLenum cap);
  bool DoIsBuffer(GLuint client_id);
  bool DoIsFramebuffer(GLuint client_id);
  bool DoIsProgram(GLuint client_id);
  bool DoIsRenderbuffer(GLuint client_id);
  bool DoIsShader(GLuint client_id);
  bool DoIsTexture(GLuint client_id);
  bool DoIsVertexArrayOES(GLuint client_id);

  // Wrapper for glLinkProgram
  void DoLinkProgram(GLuint program);

  // Helper for RegisterSharedIdsCHROMIUM.
  void DoRegisterSharedIdsCHROMIUM(
      GLuint namespace_id, GLsizei n, const GLuint* ids);

  // Wrapper for glRenderbufferStorage.
  void DoRenderbufferStorage(
      GLenum target, GLenum internalformat, GLsizei width, GLsizei height);

  // Handler for glRenderbufferStorageMultisampleCHROMIUM.
  void DoRenderbufferStorageMultisampleCHROMIUM(
      GLenum target, GLsizei samples, GLenum internalformat,
      GLsizei width, GLsizei height);

  // Handler for glRenderbufferStorageMultisampleEXT
  // (multisampled_render_to_texture).
  void DoRenderbufferStorageMultisampleEXT(
      GLenum target, GLsizei samples, GLenum internalformat,
      GLsizei width, GLsizei height);

  // Common validation for multisample extensions.
  bool ValidateRenderbufferStorageMultisample(GLsizei samples,
                                              GLenum internalformat,
                                              GLsizei width,
                                              GLsizei height);

  // Verifies that the currently bound multisample renderbuffer is valid
  // Very slow! Only done on platforms with driver bugs that return invalid
  // buffers under memory pressure
  bool VerifyMultisampleRenderbufferIntegrity(
      GLuint renderbuffer, GLenum format);

  // Wrapper for glReleaseShaderCompiler.
  void DoReleaseShaderCompiler() { }

  // Wrappers for glTexParameter functions.
  void DoTexParameterf(GLenum target, GLenum pname, GLfloat param);
  void DoTexParameteri(GLenum target, GLenum pname, GLint param);
  void DoTexParameterfv(GLenum target, GLenum pname, const GLfloat* params);
  void DoTexParameteriv(GLenum target, GLenum pname, const GLint* params);

  // Wrappers for glUniform1i and glUniform1iv as according to the GLES2
  // spec only these 2 functions can be used to set sampler uniforms.
  void DoUniform1i(GLint fake_location, GLint v0);
  void DoUniform1iv(GLint fake_location, GLsizei count, const GLint* value);
  void DoUniform2iv(GLint fake_location, GLsizei count, const GLint* value);
  void DoUniform3iv(GLint fake_location, GLsizei count, const GLint* value);
  void DoUniform4iv(GLint fake_location, GLsizei count, const GLint* value);

  // Wrappers for glUniformfv because some drivers don't correctly accept
  // bool uniforms.
  void DoUniform1fv(GLint fake_location, GLsizei count, const GLfloat* value);
  void DoUniform2fv(GLint fake_location, GLsizei count, const GLfloat* value);
  void DoUniform3fv(GLint fake_location, GLsizei count, const GLfloat* value);
  void DoUniform4fv(GLint fake_location, GLsizei count, const GLfloat* value);

  void DoUniformMatrix2fv(
      GLint fake_location, GLsizei count, GLboolean transpose,
      const GLfloat* value);
  void DoUniformMatrix3fv(
      GLint fake_location, GLsizei count, GLboolean transpose,
      const GLfloat* value);
  void DoUniformMatrix4fv(
      GLint fake_location, GLsizei count, GLboolean transpose,
      const GLfloat* value);

  bool SetVertexAttribValue(
    const char* function_name, GLuint index, const GLfloat* value);

  // Wrappers for glVertexAttrib??
  void DoVertexAttrib1f(GLuint index, GLfloat v0);
  void DoVertexAttrib2f(GLuint index, GLfloat v0, GLfloat v1);
  void DoVertexAttrib3f(GLuint index, GLfloat v0, GLfloat v1, GLfloat v2);
  void DoVertexAttrib4f(
      GLuint index, GLfloat v0, GLfloat v1, GLfloat v2, GLfloat v3);
  void DoVertexAttrib1fv(GLuint index, const GLfloat *v);
  void DoVertexAttrib2fv(GLuint index, const GLfloat *v);
  void DoVertexAttrib3fv(GLuint index, const GLfloat *v);
  void DoVertexAttrib4fv(GLuint index, const GLfloat *v);

  // Wrapper for glViewport
  void DoViewport(GLint x, GLint y, GLsizei width, GLsizei height);

  // Wrapper for glUseProgram
  void DoUseProgram(GLuint program);

  // Wrapper for glValidateProgram.
  void DoValidateProgram(GLuint program_client_id);

  void DoInsertEventMarkerEXT(GLsizei length, const GLchar* marker);
  void DoPushGroupMarkerEXT(GLsizei length, const GLchar* group);
  void DoPopGroupMarkerEXT(void);

  // Gets the number of values that will be returned by glGetXXX. Returns
  // false if pname is unknown.
  bool GetNumValuesReturnedForGLGet(GLenum pname, GLsizei* num_values);

  // Checks if the current program and vertex attributes are valid for drawing.
  bool IsDrawValid(
      const char* function_name, GLuint max_vertex_accessed, GLsizei primcount);

  // Returns true if successful, simulated will be true if attrib0 was
  // simulated.
  bool SimulateAttrib0(
      const char* function_name, GLuint max_vertex_accessed, bool* simulated);
  void RestoreStateForAttrib(GLuint attrib);

  // If an image is bound to texture, this will call Will/DidUseTexImage
  // if needed.
  void DoWillUseTexImageIfNeeded(Texture* texture, GLenum textarget);
  void DoDidUseTexImageIfNeeded(Texture* texture, GLenum textarget);

  // Returns false if textures were replaced.
  bool PrepareTexturesForRender();
  void RestoreStateForTextures();

  // Returns true if GL_FIXED attribs were simulated.
  bool SimulateFixedAttribs(
      const char* function_name,
      GLuint max_vertex_accessed, bool* simulated, GLsizei primcount);
  void RestoreStateForSimulatedFixedAttribs();

  // Handle DrawArrays and DrawElements for both instanced and non-instanced
  // cases (primcount is 0 for non-instanced).
  error::Error DoDrawArrays(
      const char* function_name,
      bool instanced, GLenum mode, GLint first, GLsizei count,
      GLsizei primcount);
  error::Error DoDrawElements(
      const char* function_name,
      bool instanced, GLenum mode, GLsizei count, GLenum type,
      int32 offset, GLsizei primcount);

  GLenum GetBindTargetForSamplerType(GLenum type) {
    DCHECK(type == GL_SAMPLER_2D || type == GL_SAMPLER_CUBE ||
           type == GL_SAMPLER_EXTERNAL_OES || type == GL_SAMPLER_2D_RECT_ARB);
    switch (type) {
      case GL_SAMPLER_2D:
        return GL_TEXTURE_2D;
      case GL_SAMPLER_CUBE:
        return GL_TEXTURE_CUBE_MAP;
      case GL_SAMPLER_EXTERNAL_OES:
        return GL_TEXTURE_EXTERNAL_OES;
      case GL_SAMPLER_2D_RECT_ARB:
        return GL_TEXTURE_RECTANGLE_ARB;
    }

    NOTREACHED();
    return 0;
  }

  // Gets the framebuffer info for a particular target.
  Framebuffer* GetFramebufferInfoForTarget(GLenum target) {
    Framebuffer* framebuffer = NULL;
    switch (target) {
      case GL_FRAMEBUFFER:
      case GL_DRAW_FRAMEBUFFER_EXT:
        framebuffer = framebuffer_state_.bound_draw_framebuffer.get();
        break;
      case GL_READ_FRAMEBUFFER_EXT:
        framebuffer = framebuffer_state_.bound_read_framebuffer.get();
        break;
      default:
        NOTREACHED();
        break;
    }
    return framebuffer;
  }

  Renderbuffer* GetRenderbufferInfoForTarget(
      GLenum target) {
    Renderbuffer* renderbuffer = NULL;
    switch (target) {
      case GL_RENDERBUFFER:
        renderbuffer = state_.bound_renderbuffer.get();
        break;
      default:
        NOTREACHED();
        break;
    }
    return renderbuffer;
  }

  // Validates the program and location for a glGetUniform call and returns
  // a SizeResult setup to receive the result. Returns true if glGetUniform
  // should be called.
  bool GetUniformSetup(
      GLuint program, GLint fake_location,
      uint32 shm_id, uint32 shm_offset,
      error::Error* error, GLint* real_location, GLuint* service_id,
      void** result, GLenum* result_type);

  virtual bool WasContextLost() OVERRIDE;
  virtual bool WasContextLostByRobustnessExtension() OVERRIDE;
  virtual void LoseContext(uint32 reset_status) OVERRIDE;

#if defined(OS_MACOSX)
  void ReleaseIOSurfaceForTexture(GLuint texture_id);
#endif

  bool ValidateCompressedTexDimensions(
      const char* function_name,
      GLint level, GLsizei width, GLsizei height, GLenum format);
  bool ValidateCompressedTexFuncData(
      const char* function_name,
      GLsizei width, GLsizei height, GLenum format, size_t size);
  bool ValidateCompressedTexSubDimensions(
    const char* function_name,
    GLenum target, GLint level, GLint xoffset, GLint yoffset,
    GLsizei width, GLsizei height, GLenum format,
    Texture* texture);

  void RenderWarning(const char* filename, int line, const std::string& msg);
  void PerformanceWarning(
      const char* filename, int line, const std::string& msg);

  const FeatureInfo::FeatureFlags& features() const {
    return feature_info_->feature_flags();
  }

  const FeatureInfo::Workarounds& workarounds() const {
    return feature_info_->workarounds();
  }

  bool ShouldDeferDraws() {
    return !offscreen_target_frame_buffer_.get() &&
           framebuffer_state_.bound_draw_framebuffer.get() == NULL &&
           surface_->DeferDraws();
  }

  bool ShouldDeferReads() {
    return !offscreen_target_frame_buffer_.get() &&
           framebuffer_state_.bound_read_framebuffer.get() == NULL &&
           surface_->DeferDraws();
  }

  error::Error WillAccessBoundFramebufferForDraw() {
    if (ShouldDeferDraws())
      return error::kDeferCommandUntilLater;
    if (!offscreen_target_frame_buffer_.get() &&
        !framebuffer_state_.bound_draw_framebuffer.get() &&
        !surface_->SetBackbufferAllocation(true))
      return error::kLostContext;
    return error::kNoError;
  }

  error::Error WillAccessBoundFramebufferForRead() {
    if (ShouldDeferReads())
      return error::kDeferCommandUntilLater;
    if (!offscreen_target_frame_buffer_.get() &&
        !framebuffer_state_.bound_read_framebuffer.get() &&
        !surface_->SetBackbufferAllocation(true))
      return error::kLostContext;
    return error::kNoError;
  }

  void ProcessPendingReadPixels();
  void FinishReadPixels(const cmds::ReadPixels& c, GLuint buffer);

  // Generate a member function prototype for each command in an automated and
  // typesafe way.
  #define GLES2_CMD_OP(name) \
     Error Handle ## name(             \
       uint32 immediate_data_size,     \
       const cmds::name& args);        \

  GLES2_COMMAND_LIST(GLES2_CMD_OP)

  #undef GLES2_CMD_OP

  // The GL context this decoder renders to on behalf of the client.
  scoped_refptr<gfx::GLSurface> surface_;
  scoped_refptr<gfx::GLContext> context_;

  // The ContextGroup for this decoder uses to track resources.
  scoped_refptr<ContextGroup> group_;

  DebugMarkerManager debug_marker_manager_;
  Logger logger_;

  // All the state for this context.
  ContextState state_;

  // Current width and height of the offscreen frame buffer.
  gfx::Size offscreen_size_;

  // Util to help with GL.
  GLES2Util util_;

  // unpack flip y as last set by glPixelStorei
  bool unpack_flip_y_;

  // unpack (un)premultiply alpha as last set by glPixelStorei
  bool unpack_premultiply_alpha_;
  bool unpack_unpremultiply_alpha_;

  // Default vertex attribs manager, used when no VAOs are bound.
  scoped_refptr<VertexAttribManager> default_vertex_attrib_manager_;

  // The buffer we bind to attrib 0 since OpenGL requires it (ES does not).
  GLuint attrib_0_buffer_id_;

  // The value currently in attrib_0.
  Vec4 attrib_0_value_;

  // Whether or not the attrib_0 buffer holds the attrib_0_value.
  bool attrib_0_buffer_matches_value_;

  // The size of attrib 0.
  GLsizei attrib_0_size_;

  // The buffer used to simulate GL_FIXED attribs.
  GLuint fixed_attrib_buffer_id_;

  // The size of fiixed attrib buffer.
  GLsizei fixed_attrib_buffer_size_;

  // The offscreen frame buffer that the client renders to. With EGL, the
  // depth and stencil buffers are separate. With regular GL there is a single
  // packed depth stencil buffer in offscreen_target_depth_render_buffer_.
  // offscreen_target_stencil_render_buffer_ is unused.
  scoped_ptr<BackFramebuffer> offscreen_target_frame_buffer_;
  scoped_ptr<BackTexture> offscreen_target_color_texture_;
  scoped_ptr<BackRenderbuffer> offscreen_target_color_render_buffer_;
  scoped_ptr<BackRenderbuffer> offscreen_target_depth_render_buffer_;
  scoped_ptr<BackRenderbuffer> offscreen_target_stencil_render_buffer_;
  GLenum offscreen_target_color_format_;
  GLenum offscreen_target_depth_format_;
  GLenum offscreen_target_stencil_format_;
  GLsizei offscreen_target_samples_;
  GLboolean offscreen_target_buffer_preserved_;

  // The copy that is saved when SwapBuffers is called.
  scoped_ptr<BackFramebuffer> offscreen_saved_frame_buffer_;
  scoped_ptr<BackTexture> offscreen_saved_color_texture_;
  scoped_refptr<TextureRef>
      offscreen_saved_color_texture_info_;

  // The copy that is used as the destination for multi-sample resolves.
  scoped_ptr<BackFramebuffer> offscreen_resolved_frame_buffer_;
  scoped_ptr<BackTexture> offscreen_resolved_color_texture_;
  GLenum offscreen_saved_color_format_;

  scoped_ptr<QueryManager> query_manager_;

  scoped_ptr<VertexArrayManager> vertex_array_manager_;

  base::Callback<void(gfx::Size, float)> resize_callback_;

  WaitSyncPointCallback wait_sync_point_callback_;

  ShaderCacheCallback shader_cache_callback_;

  scoped_ptr<AsyncPixelTransferManager> async_pixel_transfer_manager_;

  // The format of the back buffer_
  GLenum back_buffer_color_format_;
  bool back_buffer_has_depth_;
  bool back_buffer_has_stencil_;

  // Backbuffer attachments that are currently undefined.
  uint32 backbuffer_needs_clear_bits_;

  // The current decoder error.
  error::Error current_decoder_error_;

  bool use_shader_translator_;
  scoped_refptr<ShaderTranslator> vertex_translator_;
  scoped_refptr<ShaderTranslator> fragment_translator_;

  DisallowedFeatures disallowed_features_;

  // Cached from ContextGroup
  const Validators* validators_;
  scoped_refptr<FeatureInfo> feature_info_;

  int frame_number_;

  bool has_robustness_extension_;
  GLenum reset_status_;
  bool reset_by_robustness_extension_;
  bool supports_post_sub_buffer_;

  // These flags are used to override the state of the shared feature_info_
  // member.  Because the same FeatureInfo instance may be shared among many
  // contexts, the assumptions on the availablity of extensions in WebGL
  // contexts may be broken.  These flags override the shared state to preserve
  // WebGL semantics.
  bool force_webgl_glsl_validation_;
  bool derivatives_explicitly_enabled_;
  bool frag_depth_explicitly_enabled_;
  bool draw_buffers_explicitly_enabled_;

  bool compile_shader_always_succeeds_;

  // An optional behaviour to lose the context and group when OOM.
  bool lose_context_when_out_of_memory_;

  // Log extra info.
  bool service_logging_;

#if defined(OS_MACOSX)
  typedef std::map<GLuint, CFTypeRef> TextureToIOSurfaceMap;
  TextureToIOSurfaceMap texture_to_io_surface_map_;
#endif

  scoped_ptr<CopyTextureCHROMIUMResourceManager> copy_texture_CHROMIUM_;

  // Cached values of the currently assigned viewport dimensions.
  GLsizei viewport_max_width_;
  GLsizei viewport_max_height_;

  // Command buffer stats.
  base::TimeDelta total_processing_commands_time_;

  // States related to each manager.
  DecoderTextureState texture_state_;
  DecoderFramebufferState framebuffer_state_;

  scoped_ptr<GPUTracer> gpu_tracer_;
  scoped_ptr<GPUStateTracer> gpu_state_tracer_;
  int gpu_trace_level_;
  bool gpu_trace_commands_;

  std::queue<linked_ptr<FenceCallback> > pending_readpixel_fences_;

  // Used to validate multisample renderbuffers if needed
  GLuint validation_texture_;
  GLuint validation_fbo_multisample_;
  GLuint validation_fbo_;

  DISALLOW_COPY_AND_ASSIGN(GLES2DecoderImpl);
};

ScopedGLErrorSuppressor::ScopedGLErrorSuppressor(
    const char* function_name, ErrorState* error_state)
    : function_name_(function_name),
      error_state_(error_state) {
  ERRORSTATE_COPY_REAL_GL_ERRORS_TO_WRAPPER(error_state_, function_name_);
}

ScopedGLErrorSuppressor::~ScopedGLErrorSuppressor() {
  ERRORSTATE_CLEAR_REAL_GL_ERRORS(error_state_, function_name_);
}

static void RestoreCurrentTextureBindings(ContextState* state, GLenum target) {
  TextureUnit& info = state->texture_units[0];
  GLuint last_id;
  scoped_refptr<TextureRef> texture_ref;
  switch (target) {
    case GL_TEXTURE_2D:
      texture_ref = info.bound_texture_2d;
      break;
    case GL_TEXTURE_CUBE_MAP:
      texture_ref = info.bound_texture_cube_map;
      break;
    case GL_TEXTURE_EXTERNAL_OES:
      texture_ref = info.bound_texture_external_oes;
      break;
    case GL_TEXTURE_RECTANGLE_ARB:
      texture_ref = info.bound_texture_rectangle_arb;
      break;
    default:
      NOTREACHED();
      break;
  }
  if (texture_ref.get()) {
    last_id = texture_ref->service_id();
  } else {
    last_id = 0;
  }

  glBindTexture(target, last_id);
  glActiveTexture(GL_TEXTURE0 + state->active_texture_unit);
}

ScopedTextureBinder::ScopedTextureBinder(ContextState* state,
                                         GLuint id,
                                         GLenum target)
    : state_(state),
      target_(target) {
  ScopedGLErrorSuppressor suppressor(
      "ScopedTextureBinder::ctor", state_->GetErrorState());

  // TODO(apatrick): Check if there are any other states that need to be reset
  // before binding a new texture.
  glActiveTexture(GL_TEXTURE0);
  glBindTexture(target, id);
}

ScopedTextureBinder::~ScopedTextureBinder() {
  ScopedGLErrorSuppressor suppressor(
      "ScopedTextureBinder::dtor", state_->GetErrorState());
  RestoreCurrentTextureBindings(state_, target_);
}

ScopedRenderBufferBinder::ScopedRenderBufferBinder(ContextState* state,
                                                   GLuint id)
    : state_(state) {
  ScopedGLErrorSuppressor suppressor(
      "ScopedRenderBufferBinder::ctor", state_->GetErrorState());
  glBindRenderbufferEXT(GL_RENDERBUFFER, id);
}

ScopedRenderBufferBinder::~ScopedRenderBufferBinder() {
  ScopedGLErrorSuppressor suppressor(
      "ScopedRenderBufferBinder::dtor", state_->GetErrorState());
  state_->RestoreRenderbufferBindings();
}

ScopedFrameBufferBinder::ScopedFrameBufferBinder(GLES2DecoderImpl* decoder,
                                                 GLuint id)
    : decoder_(decoder) {
  ScopedGLErrorSuppressor suppressor(
      "ScopedFrameBufferBinder::ctor", decoder_->GetErrorState());
  glBindFramebufferEXT(GL_FRAMEBUFFER, id);
  decoder->OnFboChanged();
}

ScopedFrameBufferBinder::~ScopedFrameBufferBinder() {
  ScopedGLErrorSuppressor suppressor(
      "ScopedFrameBufferBinder::dtor", decoder_->GetErrorState());
  decoder_->RestoreCurrentFramebufferBindings();
}

ScopedResolvedFrameBufferBinder::ScopedResolvedFrameBufferBinder(
    GLES2DecoderImpl* decoder, bool enforce_internal_framebuffer, bool internal)
    : decoder_(decoder) {
  resolve_and_bind_ = (
      decoder_->offscreen_target_frame_buffer_.get() &&
      decoder_->IsOffscreenBufferMultisampled() &&
      (!decoder_->framebuffer_state_.bound_read_framebuffer.get() ||
       enforce_internal_framebuffer));
  if (!resolve_and_bind_)
    return;

  ScopedGLErrorSuppressor suppressor(
      "ScopedResolvedFrameBufferBinder::ctor", decoder_->GetErrorState());
  glBindFramebufferEXT(GL_READ_FRAMEBUFFER_EXT,
                       decoder_->offscreen_target_frame_buffer_->id());
  GLuint targetid;
  if (internal) {
    if (!decoder_->offscreen_resolved_frame_buffer_.get()) {
      decoder_->offscreen_resolved_frame_buffer_.reset(
          new BackFramebuffer(decoder_));
      decoder_->offscreen_resolved_frame_buffer_->Create();
      decoder_->offscreen_resolved_color_texture_.reset(
          new BackTexture(decoder->memory_tracker(), &decoder->state_));
      decoder_->offscreen_resolved_color_texture_->Create();

      DCHECK(decoder_->offscreen_saved_color_format_);
      decoder_->offscreen_resolved_color_texture_->AllocateStorage(
          decoder_->offscreen_size_, decoder_->offscreen_saved_color_format_,
          false);
      decoder_->offscreen_resolved_frame_buffer_->AttachRenderTexture(
          decoder_->offscreen_resolved_color_texture_.get());
      if (decoder_->offscreen_resolved_frame_buffer_->CheckStatus() !=
          GL_FRAMEBUFFER_COMPLETE) {
        LOG(ERROR) << "ScopedResolvedFrameBufferBinder failed "
                   << "because offscreen resolved FBO was incomplete.";
        return;
      }
    }
    targetid = decoder_->offscreen_resolved_frame_buffer_->id();
  } else {
    targetid = decoder_->offscreen_saved_frame_buffer_->id();
  }
  glBindFramebufferEXT(GL_DRAW_FRAMEBUFFER_EXT, targetid);
  const int width = decoder_->offscreen_size_.width();
  const int height = decoder_->offscreen_size_.height();
  glDisable(GL_SCISSOR_TEST);
  decoder->BlitFramebufferHelper(0,
                                 0,
                                 width,
                                 height,
                                 0,
                                 0,
                                 width,
                                 height,
                                 GL_COLOR_BUFFER_BIT,
                                 GL_NEAREST);
  glBindFramebufferEXT(GL_FRAMEBUFFER, targetid);
}

ScopedResolvedFrameBufferBinder::~ScopedResolvedFrameBufferBinder() {
  if (!resolve_and_bind_)
    return;

  ScopedGLErrorSuppressor suppressor(
      "ScopedResolvedFrameBufferBinder::dtor", decoder_->GetErrorState());
  decoder_->RestoreCurrentFramebufferBindings();
  if (decoder_->state_.enable_flags.scissor_test) {
    glEnable(GL_SCISSOR_TEST);
  }
}

BackTexture::BackTexture(
    MemoryTracker* memory_tracker,
    ContextState* state)
    : memory_tracker_(memory_tracker, MemoryTracker::kUnmanaged),
      state_(state),
      bytes_allocated_(0),
      id_(0) {
}

BackTexture::~BackTexture() {
  // This does not destroy the render texture because that would require that
  // the associated GL context was current. Just check that it was explicitly
  // destroyed.
  DCHECK_EQ(id_, 0u);
}

void BackTexture::Create() {
  ScopedGLErrorSuppressor suppressor("BackTexture::Create",
                                     state_->GetErrorState());
  Destroy();
  glGenTextures(1, &id_);
  ScopedTextureBinder binder(state_, id_, GL_TEXTURE_2D);
  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);

  // TODO(apatrick): Attempt to diagnose crbug.com/97775. If SwapBuffers is
  // never called on an offscreen context, no data will ever be uploaded to the
  // saved offscreen color texture (it is deferred until to when SwapBuffers
  // is called). My idea is that some nvidia drivers might have a bug where
  // deleting a texture that has never been populated might cause a
  // crash.
  glTexImage2D(
      GL_TEXTURE_2D, 0, GL_RGBA, 16, 16, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL);

  bytes_allocated_ = 16u * 16u * 4u;
  memory_tracker_.TrackMemAlloc(bytes_allocated_);
}

bool BackTexture::AllocateStorage(
    const gfx::Size& size, GLenum format, bool zero) {
  DCHECK_NE(id_, 0u);
  ScopedGLErrorSuppressor suppressor("BackTexture::AllocateStorage",
                                     state_->GetErrorState());
  ScopedTextureBinder binder(state_, id_, GL_TEXTURE_2D);
  uint32 image_size = 0;
  GLES2Util::ComputeImageDataSizes(
      size.width(), size.height(), format, GL_UNSIGNED_BYTE, 8, &image_size,
      NULL, NULL);

  if (!memory_tracker_.EnsureGPUMemoryAvailable(image_size)) {
    return false;
  }

  scoped_ptr<char[]> zero_data;
  if (zero) {
    zero_data.reset(new char[image_size]);
    memset(zero_data.get(), 0, image_size);
  }

  glTexImage2D(GL_TEXTURE_2D,
               0,  // mip level
               format,
               size.width(),
               size.height(),
               0,  // border
               format,
               GL_UNSIGNED_BYTE,
               zero_data.get());

  size_ = size;

  bool success = glGetError() == GL_NO_ERROR;
  if (success) {
    memory_tracker_.TrackMemFree(bytes_allocated_);
    bytes_allocated_ = image_size;
    memory_tracker_.TrackMemAlloc(bytes_allocated_);
  }
  return success;
}

void BackTexture::Copy(const gfx::Size& size, GLenum format) {
  DCHECK_NE(id_, 0u);
  ScopedGLErrorSuppressor suppressor("BackTexture::Copy",
                                     state_->GetErrorState());
  ScopedTextureBinder binder(state_, id_, GL_TEXTURE_2D);
  glCopyTexImage2D(GL_TEXTURE_2D,
                   0,  // level
                   format,
                   0, 0,
                   size.width(),
                   size.height(),
                   0);  // border
}

void BackTexture::Destroy() {
  if (id_ != 0) {
    ScopedGLErrorSuppressor suppressor("BackTexture::Destroy",
                                       state_->GetErrorState());
    glDeleteTextures(1, &id_);
    id_ = 0;
  }
  memory_tracker_.TrackMemFree(bytes_allocated_);
  bytes_allocated_ = 0;
}

void BackTexture::Invalidate() {
  id_ = 0;
}

BackRenderbuffer::BackRenderbuffer(
    RenderbufferManager* renderbuffer_manager,
    MemoryTracker* memory_tracker,
    ContextState* state)
    : renderbuffer_manager_(renderbuffer_manager),
      memory_tracker_(memory_tracker, MemoryTracker::kUnmanaged),
      state_(state),
      bytes_allocated_(0),
      id_(0) {
}

BackRenderbuffer::~BackRenderbuffer() {
  // This does not destroy the render buffer because that would require that
  // the associated GL context was current. Just check that it was explicitly
  // destroyed.
  DCHECK_EQ(id_, 0u);
}

void BackRenderbuffer::Create() {
  ScopedGLErrorSuppressor suppressor("BackRenderbuffer::Create",
                                     state_->GetErrorState());
  Destroy();
  glGenRenderbuffersEXT(1, &id_);
}

bool BackRenderbuffer::AllocateStorage(const FeatureInfo* feature_info,
                                       const gfx::Size& size,
                                       GLenum format,
                                       GLsizei samples) {
  ScopedGLErrorSuppressor suppressor(
      "BackRenderbuffer::AllocateStorage", state_->GetErrorState());
  ScopedRenderBufferBinder binder(state_, id_);

  uint32 estimated_size = 0;
  if (!renderbuffer_manager_->ComputeEstimatedRenderbufferSize(
           size.width(), size.height(), samples, format, &estimated_size)) {
    return false;
  }

  if (!memory_tracker_.EnsureGPUMemoryAvailable(estimated_size)) {
    return false;
  }

  if (samples <= 1) {
    glRenderbufferStorageEXT(GL_RENDERBUFFER,
                             format,
                             size.width(),
                             size.height());
  } else {
    GLES2DecoderImpl::RenderbufferStorageMultisampleHelper(feature_info,
                                                           GL_RENDERBUFFER,
                                                           samples,
                                                           format,
                                                           size.width(),
                                                           size.height());
  }
  bool success = glGetError() == GL_NO_ERROR;
  if (success) {
    // Mark the previously allocated bytes as free.
    memory_tracker_.TrackMemFree(bytes_allocated_);
    bytes_allocated_ = estimated_size;
    // Track the newly allocated bytes.
    memory_tracker_.TrackMemAlloc(bytes_allocated_);
  }
  return success;
}

void BackRenderbuffer::Destroy() {
  if (id_ != 0) {
    ScopedGLErrorSuppressor suppressor("BackRenderbuffer::Destroy",
                                       state_->GetErrorState());
    glDeleteRenderbuffersEXT(1, &id_);
    id_ = 0;
  }
  memory_tracker_.TrackMemFree(bytes_allocated_);
  bytes_allocated_ = 0;
}

void BackRenderbuffer::Invalidate() {
  id_ = 0;
}

BackFramebuffer::BackFramebuffer(GLES2DecoderImpl* decoder)
    : decoder_(decoder),
      id_(0) {
}

BackFramebuffer::~BackFramebuffer() {
  // This does not destroy the frame buffer because that would require that
  // the associated GL context was current. Just check that it was explicitly
  // destroyed.
  DCHECK_EQ(id_, 0u);
}

void BackFramebuffer::Create() {
  ScopedGLErrorSuppressor suppressor("BackFramebuffer::Create",
                                     decoder_->GetErrorState());
  Destroy();
  glGenFramebuffersEXT(1, &id_);
}

void BackFramebuffer::AttachRenderTexture(BackTexture* texture) {
  DCHECK_NE(id_, 0u);
  ScopedGLErrorSuppressor suppressor(
      "BackFramebuffer::AttachRenderTexture", decoder_->GetErrorState());
  ScopedFrameBufferBinder binder(decoder_, id_);
  GLuint attach_id = texture ? texture->id() : 0;
  glFramebufferTexture2DEXT(GL_FRAMEBUFFER,
                            GL_COLOR_ATTACHMENT0,
                            GL_TEXTURE_2D,
                            attach_id,
                            0);
}

void BackFramebuffer::AttachRenderBuffer(GLenum target,
                                         BackRenderbuffer* render_buffer) {
  DCHECK_NE(id_, 0u);
  ScopedGLErrorSuppressor suppressor(
      "BackFramebuffer::AttachRenderBuffer", decoder_->GetErrorState());
  ScopedFrameBufferBinder binder(decoder_, id_);
  GLuint attach_id = render_buffer ? render_buffer->id() : 0;
  glFramebufferRenderbufferEXT(GL_FRAMEBUFFER,
                               target,
                               GL_RENDERBUFFER,
                               attach_id);
}

void BackFramebuffer::Destroy() {
  if (id_ != 0) {
    ScopedGLErrorSuppressor suppressor("BackFramebuffer::Destroy",
                                       decoder_->GetErrorState());
    glDeleteFramebuffersEXT(1, &id_);
    id_ = 0;
  }
}

void BackFramebuffer::Invalidate() {
  id_ = 0;
}

GLenum BackFramebuffer::CheckStatus() {
  DCHECK_NE(id_, 0u);
  ScopedGLErrorSuppressor suppressor("BackFramebuffer::CheckStatus",
                                     decoder_->GetErrorState());
  ScopedFrameBufferBinder binder(decoder_, id_);
  return glCheckFramebufferStatusEXT(GL_FRAMEBUFFER);
}

GLES2Decoder* GLES2Decoder::Create(ContextGroup* group) {
  return new GLES2DecoderImpl(group);
}

GLES2DecoderImpl::GLES2DecoderImpl(ContextGroup* group)
    : GLES2Decoder(),
      group_(group),
      logger_(&debug_marker_manager_),
      state_(group_->feature_info(), this, &logger_),
      unpack_flip_y_(false),
      unpack_premultiply_alpha_(false),
      unpack_unpremultiply_alpha_(false),
      attrib_0_buffer_id_(0),
      attrib_0_buffer_matches_value_(true),
      attrib_0_size_(0),
      fixed_attrib_buffer_id_(0),
      fixed_attrib_buffer_size_(0),
      offscreen_target_color_format_(0),
      offscreen_target_depth_format_(0),
      offscreen_target_stencil_format_(0),
      offscreen_target_samples_(0),
      offscreen_target_buffer_preserved_(true),
      offscreen_saved_color_format_(0),
      back_buffer_color_format_(0),
      back_buffer_has_depth_(false),
      back_buffer_has_stencil_(false),
      backbuffer_needs_clear_bits_(0),
      current_decoder_error_(error::kNoError),
      use_shader_translator_(true),
      validators_(group_->feature_info()->validators()),
      feature_info_(group_->feature_info()),
      frame_number_(0),
      has_robustness_extension_(false),
      reset_status_(GL_NO_ERROR),
      reset_by_robustness_extension_(false),
      supports_post_sub_buffer_(false),
      force_webgl_glsl_validation_(false),
      derivatives_explicitly_enabled_(false),
      frag_depth_explicitly_enabled_(false),
      draw_buffers_explicitly_enabled_(false),
      compile_shader_always_succeeds_(false),
      lose_context_when_out_of_memory_(false),
      service_logging_(CommandLine::ForCurrentProcess()->HasSwitch(
          switches::kEnableGPUServiceLoggingGPU)),
      viewport_max_width_(0),
      viewport_max_height_(0),
      texture_state_(group_->feature_info()
                         ->workarounds()
                         .texsubimage2d_faster_than_teximage2d),
      validation_texture_(0),
      validation_fbo_multisample_(0),
      validation_fbo_(0) {
  DCHECK(group);

  attrib_0_value_.v[0] = 0.0f;
  attrib_0_value_.v[1] = 0.0f;
  attrib_0_value_.v[2] = 0.0f;
  attrib_0_value_.v[3] = 1.0f;

  // The shader translator is used for WebGL even when running on EGL
  // because additional restrictions are needed (like only enabling
  // GL_OES_standard_derivatives on demand).  It is used for the unit
  // tests because GLES2DecoderWithShaderTest.GetShaderInfoLogValidArgs passes
  // the empty string to CompileShader and this is not a valid shader.
  if (gfx::GetGLImplementation() == gfx::kGLImplementationMockGL ||
      CommandLine::ForCurrentProcess()->HasSwitch(
          switches::kDisableGLSLTranslator)) {
    use_shader_translator_ = false;
  }
}

GLES2DecoderImpl::~GLES2DecoderImpl() {
}

bool GLES2DecoderImpl::Initialize(
    const scoped_refptr<gfx::GLSurface>& surface,
    const scoped_refptr<gfx::GLContext>& context,
    bool offscreen,
    const gfx::Size& size,
    const DisallowedFeatures& disallowed_features,
    const std::vector<int32>& attribs) {
  TRACE_EVENT0("gpu", "GLES2DecoderImpl::Initialize");
  DCHECK(context->IsCurrent(surface.get()));
  DCHECK(!context_.get());

  set_initialized();
  gpu_tracer_ = GPUTracer::Create(this);
  gpu_state_tracer_ = GPUStateTracer::Create(&state_);
  // TODO(vmiura): Enable changing gpu_trace_level_ at runtime
  gpu_trace_level_ = 2;
  gpu_trace_commands_ = false;

  if (CommandLine::ForCurrentProcess()->HasSwitch(
      switches::kEnableGPUDebugging)) {
    set_debug(true);
  }

  if (CommandLine::ForCurrentProcess()->HasSwitch(
      switches::kEnableGPUCommandLogging)) {
    set_log_commands(true);
  }

  compile_shader_always_succeeds_ = CommandLine::ForCurrentProcess()->HasSwitch(
      switches::kCompileShaderAlwaysSucceeds);


  // Take ownership of the context and surface. The surface can be replaced with
  // SetSurface.
  context_ = context;
  surface_ = surface;

  ContextCreationAttribHelper attrib_parser;
  if (!attrib_parser.Parse(attribs))
    return false;

  // Save the loseContextWhenOutOfMemory context creation attribute.
  lose_context_when_out_of_memory_ =
      attrib_parser.lose_context_when_out_of_memory_;

  // If the failIfMajorPerformanceCaveat context creation attribute was true
  // and we are using a software renderer, fail.
  if (attrib_parser.fail_if_major_perf_caveat_ &&
      feature_info_->feature_flags().is_swiftshader) {
    group_ = NULL;  // Must not destroy ContextGroup if it is not initialized.
    Destroy(true);
    return false;
  }

  if (!group_->Initialize(this, disallowed_features)) {
    LOG(ERROR) << "GpuScheduler::InitializeCommon failed because group "
               << "failed to initialize.";
    group_ = NULL;  // Must not destroy ContextGroup if it is not initialized.
    Destroy(true);
    return false;
  }
  CHECK_GL_ERROR();

  disallowed_features_ = disallowed_features;

  state_.attrib_values.resize(group_->max_vertex_attribs());
  default_vertex_attrib_manager_ = new VertexAttribManager();
  default_vertex_attrib_manager_->Initialize(
      group_->max_vertex_attribs(),
      feature_info_->workarounds().init_vertex_attributes);

  // vertex_attrib_manager is set to default_vertex_attrib_manager_ by this call
  DoBindVertexArrayOES(0);

  query_manager_.reset(new QueryManager(this, feature_info_.get()));
  vertex_array_manager_.reset(new VertexArrayManager());

  util_.set_num_compressed_texture_formats(
      validators_->compressed_texture_format.GetValues().size());

  if (gfx::GetGLImplementation() != gfx::kGLImplementationEGLGLES2) {
    // We have to enable vertex array 0 on OpenGL or it won't render. Note that
    // OpenGL ES 2.0 does not have this issue.
    glEnableVertexAttribArray(0);
  }
  glGenBuffersARB(1, &attrib_0_buffer_id_);
  glBindBuffer(GL_ARRAY_BUFFER, attrib_0_buffer_id_);
  glVertexAttribPointer(0, 1, GL_FLOAT, GL_FALSE, 0, NULL);
  glBindBuffer(GL_ARRAY_BUFFER, 0);
  glGenBuffersARB(1, &fixed_attrib_buffer_id_);

  state_.texture_units.resize(group_->max_texture_units());
  for (uint32 tt = 0; tt < state_.texture_units.size(); ++tt) {
    glActiveTexture(GL_TEXTURE0 + tt);
    // We want the last bind to be 2D.
    TextureRef* ref;
    if (features().oes_egl_image_external) {
      ref = texture_manager()->GetDefaultTextureInfo(
          GL_TEXTURE_EXTERNAL_OES);
      state_.texture_units[tt].bound_texture_external_oes = ref;
      glBindTexture(GL_TEXTURE_EXTERNAL_OES, ref->service_id());
    }
    if (features().arb_texture_rectangle) {
      ref = texture_manager()->GetDefaultTextureInfo(
          GL_TEXTURE_RECTANGLE_ARB);
      state_.texture_units[tt].bound_texture_rectangle_arb = ref;
      glBindTexture(GL_TEXTURE_RECTANGLE_ARB, ref->service_id());
    }
    ref = texture_manager()->GetDefaultTextureInfo(GL_TEXTURE_CUBE_MAP);
    state_.texture_units[tt].bound_texture_cube_map = ref;
    glBindTexture(GL_TEXTURE_CUBE_MAP, ref->service_id());
    ref = texture_manager()->GetDefaultTextureInfo(GL_TEXTURE_2D);
    state_.texture_units[tt].bound_texture_2d = ref;
    glBindTexture(GL_TEXTURE_2D, ref->service_id());
  }
  glActiveTexture(GL_TEXTURE0);
  CHECK_GL_ERROR();

  if (offscreen) {
    if (attrib_parser.samples_ > 0 && attrib_parser.sample_buffers_ > 0 &&
        features().chromium_framebuffer_multisample) {
      // Per ext_framebuffer_multisample spec, need max bound on sample count.
      // max_sample_count must be initialized to a sane value.  If
      // glGetIntegerv() throws a GL error, it leaves its argument unchanged.
      GLint max_sample_count = 1;
      glGetIntegerv(GL_MAX_SAMPLES_EXT, &max_sample_count);
      offscreen_target_samples_ = std::min(attrib_parser.samples_,
                                           max_sample_count);
    } else {
      offscreen_target_samples_ = 1;
    }
    offscreen_target_buffer_preserved_ = attrib_parser.buffer_preserved_;

    if (gfx::GetGLImplementation() == gfx::kGLImplementationEGLGLES2) {
      const bool rgb8_supported =
          context_->HasExtension("GL_OES_rgb8_rgba8");
      // The only available default render buffer formats in GLES2 have very
      // little precision.  Don't enable multisampling unless 8-bit render
      // buffer formats are available--instead fall back to 8-bit textures.
      if (rgb8_supported && offscreen_target_samples_ > 1) {
        offscreen_target_color_format_ = attrib_parser.alpha_size_ > 0 ?
            GL_RGBA8 : GL_RGB8;
      } else {
        offscreen_target_samples_ = 1;
        offscreen_target_color_format_ = attrib_parser.alpha_size_ > 0 ?
            GL_RGBA : GL_RGB;
      }

      // ANGLE only supports packed depth/stencil formats, so use it if it is
      // available.
      const bool depth24_stencil8_supported =
          feature_info_->feature_flags().packed_depth24_stencil8;
      VLOG(1) << "GL_OES_packed_depth_stencil "
              << (depth24_stencil8_supported ? "" : "not ") << "supported.";
      if ((attrib_parser.depth_size_ > 0 || attrib_parser.stencil_size_ > 0) &&
          depth24_stencil8_supported) {
        offscreen_target_depth_format_ = GL_DEPTH24_STENCIL8;
        offscreen_target_stencil_format_ = 0;
      } else {
        // It may be the case that this depth/stencil combination is not
        // supported, but this will be checked later by CheckFramebufferStatus.
        offscreen_target_depth_format_ = attrib_parser.depth_size_ > 0 ?
            GL_DEPTH_COMPONENT16 : 0;
        offscreen_target_stencil_format_ = attrib_parser.stencil_size_ > 0 ?
            GL_STENCIL_INDEX8 : 0;
      }
    } else {
      offscreen_target_color_format_ = attrib_parser.alpha_size_ > 0 ?
          GL_RGBA : GL_RGB;

      // If depth is requested at all, use the packed depth stencil format if
      // it's available, as some desktop GL drivers don't support any non-packed
      // formats for depth attachments.
      const bool depth24_stencil8_supported =
          feature_info_->feature_flags().packed_depth24_stencil8;
      VLOG(1) << "GL_EXT_packed_depth_stencil "
              << (depth24_stencil8_supported ? "" : "not ") << "supported.";

      if ((attrib_parser.depth_size_ > 0 || attrib_parser.stencil_size_ > 0) &&
          depth24_stencil8_supported) {
        offscreen_target_depth_format_ = GL_DEPTH24_STENCIL8;
        offscreen_target_stencil_format_ = 0;
      } else {
        offscreen_target_depth_format_ = attrib_parser.depth_size_ > 0 ?
            GL_DEPTH_COMPONENT : 0;
        offscreen_target_stencil_format_ = attrib_parser.stencil_size_ > 0 ?
            GL_STENCIL_INDEX : 0;
      }
    }

    offscreen_saved_color_format_ = attrib_parser.alpha_size_ > 0 ?
        GL_RGBA : GL_RGB;

    // Create the target frame buffer. This is the one that the client renders
    // directly to.
    offscreen_target_frame_buffer_.reset(new BackFramebuffer(this));
    offscreen_target_frame_buffer_->Create();
    // Due to GLES2 format limitations, either the color texture (for
    // non-multisampling) or the color render buffer (for multisampling) will be
    // attached to the offscreen frame buffer.  The render buffer has more
    // limited formats available to it, but the texture can't do multisampling.
    if (IsOffscreenBufferMultisampled()) {
      offscreen_target_color_render_buffer_.reset(new BackRenderbuffer(
          renderbuffer_manager(), memory_tracker(), &state_));
      offscreen_target_color_render_buffer_->Create();
    } else {
      offscreen_target_color_texture_.reset(new BackTexture(
          memory_tracker(), &state_));
      offscreen_target_color_texture_->Create();
    }
    offscreen_target_depth_render_buffer_.reset(new BackRenderbuffer(
        renderbuffer_manager(), memory_tracker(), &state_));
    offscreen_target_depth_render_buffer_->Create();
    offscreen_target_stencil_render_buffer_.reset(new BackRenderbuffer(
        renderbuffer_manager(), memory_tracker(), &state_));
    offscreen_target_stencil_render_buffer_->Create();

    // Create the saved offscreen texture. The target frame buffer is copied
    // here when SwapBuffers is called.
    offscreen_saved_frame_buffer_.reset(new BackFramebuffer(this));
    offscreen_saved_frame_buffer_->Create();
    //
    offscreen_saved_color_texture_.reset(new BackTexture(
        memory_tracker(), &state_));
    offscreen_saved_color_texture_->Create();

    // Allocate the render buffers at their initial size and check the status
    // of the frame buffers is okay.
    if (!ResizeOffscreenFrameBuffer(size)) {
      LOG(ERROR) << "Could not allocate offscreen buffer storage.";
      Destroy(true);
      return false;
    }

    // Allocate the offscreen saved color texture.
    DCHECK(offscreen_saved_color_format_);
    offscreen_saved_color_texture_->AllocateStorage(
        gfx::Size(1, 1), offscreen_saved_color_format_, true);

    offscreen_saved_frame_buffer_->AttachRenderTexture(
        offscreen_saved_color_texture_.get());
    if (offscreen_saved_frame_buffer_->CheckStatus() !=
        GL_FRAMEBUFFER_COMPLETE) {
      LOG(ERROR) << "Offscreen saved FBO was incomplete.";
      Destroy(true);
      return false;
    }

    // Bind to the new default frame buffer (the offscreen target frame buffer).
    // This should now be associated with ID zero.
    DoBindFramebuffer(GL_FRAMEBUFFER, 0);
  } else {
    glBindFramebufferEXT(GL_FRAMEBUFFER, GetBackbufferServiceId());
    // These are NOT if the back buffer has these proprorties. They are
    // if we want the command buffer to enforce them regardless of what
    // the real backbuffer is assuming the real back buffer gives us more than
    // we ask for. In other words, if we ask for RGB and we get RGBA then we'll
    // make it appear RGB. If on the other hand we ask for RGBA nd get RGB we
    // can't do anything about that.

    GLint v = 0;
    glGetIntegerv(GL_ALPHA_BITS, &v);
    // This checks if the user requested RGBA and we have RGBA then RGBA. If the
    // user requested RGB then RGB. If the user did not specify a preference
    // than use whatever we were given. Same for DEPTH and STENCIL.
    back_buffer_color_format_ =
        (attrib_parser.alpha_size_ != 0 && v > 0) ? GL_RGBA : GL_RGB;
    glGetIntegerv(GL_DEPTH_BITS, &v);
    back_buffer_has_depth_ = attrib_parser.depth_size_ != 0 && v > 0;
    glGetIntegerv(GL_STENCIL_BITS, &v);
    back_buffer_has_stencil_ = attrib_parser.stencil_size_ != 0 && v > 0;
  }

  // OpenGL ES 2.0 implicitly enables the desktop GL capability
  // VERTEX_PROGRAM_POINT_SIZE and doesn't expose this enum. This fact
  // isn't well documented; it was discovered in the Khronos OpenGL ES
  // mailing list archives. It also implicitly enables the desktop GL
  // capability GL_POINT_SPRITE to provide access to the gl_PointCoord
  // variable in fragment shaders.
  if (gfx::GetGLImplementation() != gfx::kGLImplementationEGLGLES2) {
    glEnable(GL_VERTEX_PROGRAM_POINT_SIZE);
    glEnable(GL_POINT_SPRITE);
  }

  has_robustness_extension_ =
      context->HasExtension("GL_ARB_robustness") ||
      context->HasExtension("GL_EXT_robustness");

  if (!InitializeShaderTranslator()) {
    return false;
  }

  state_.viewport_width = size.width();
  state_.viewport_height = size.height();

  GLint viewport_params[4] = { 0 };
  glGetIntegerv(GL_MAX_VIEWPORT_DIMS, viewport_params);
  viewport_max_width_ = viewport_params[0];
  viewport_max_height_ = viewport_params[1];

  state_.scissor_width = state_.viewport_width;
  state_.scissor_height = state_.viewport_height;

  // Set all the default state because some GL drivers get it wrong.
  state_.InitCapabilities();
  state_.InitState();
  glActiveTexture(GL_TEXTURE0 + state_.active_texture_unit);

  DoBindBuffer(GL_ARRAY_BUFFER, 0);
  DoBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
  DoBindFramebuffer(GL_FRAMEBUFFER, 0);
  DoBindRenderbuffer(GL_RENDERBUFFER, 0);

  bool call_gl_clear = true;
#if defined(OS_ANDROID)
  // Temporary workaround for Android WebView because this clear ignores the
  // clip and corrupts that external UI of the App. Not calling glClear is ok
  // because the system already clears the buffer before each draw. Proper
  // fix might be setting the scissor clip properly before initialize. See
  // crbug.com/259023 for details.
  call_gl_clear = surface_->GetHandle();
#endif
  if (call_gl_clear) {
    // Clear the backbuffer.
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);
  }

  supports_post_sub_buffer_ = surface->SupportsPostSubBuffer();
  if (feature_info_->workarounds()
          .disable_post_sub_buffers_for_onscreen_surfaces &&
      !surface->IsOffscreen())
    supports_post_sub_buffer_ = false;

  if (feature_info_->workarounds().reverse_point_sprite_coord_origin) {
    glPointParameteri(GL_POINT_SPRITE_COORD_ORIGIN, GL_LOWER_LEFT);
  }

  if (feature_info_->workarounds().unbind_fbo_on_context_switch) {
    context_->SetUnbindFboOnMakeCurrent();
  }

  if (feature_info_->workarounds().release_image_after_use) {
    image_manager()->SetReleaseAfterUse();
  }

  // Only compositor contexts are known to use only the subset of GL
  // that can be safely migrated between the iGPU and the dGPU. Mark
  // those contexts as safe to forcibly transition between the GPUs.
  // http://crbug.com/180876, http://crbug.com/227228
  if (!offscreen)
    context_->SetSafeToForceGpuSwitch();

  async_pixel_transfer_manager_.reset(
      AsyncPixelTransferManager::Create(context.get()));
  async_pixel_transfer_manager_->Initialize(texture_manager());

  framebuffer_manager()->AddObserver(this);

  return true;
}

Capabilities GLES2DecoderImpl::GetCapabilities() {
  DCHECK(initialized());

  Capabilities caps;

  caps.fast_npot_mo8_textures =
      feature_info_->workarounds().enable_chromium_fast_npot_mo8_textures;
  caps.egl_image_external =
      feature_info_->feature_flags().oes_egl_image_external;
  caps.texture_format_bgra8888 =
      feature_info_->feature_flags().ext_texture_format_bgra8888;
  caps.texture_format_etc1 =
      feature_info_->feature_flags().oes_compressed_etc1_rgb8_texture;
  caps.texture_rectangle = feature_info_->feature_flags().arb_texture_rectangle;
  caps.texture_usage = feature_info_->feature_flags().angle_texture_usage;
  caps.texture_storage = feature_info_->feature_flags().ext_texture_storage;
  caps.discard_framebuffer =
      feature_info_->feature_flags().ext_discard_framebuffer;

#if defined(OS_MACOSX)
  // This is unconditionally true on mac, no need to test for it at runtime.
  caps.iosurface = true;
#endif

  caps.post_sub_buffer = supports_post_sub_buffer_;

  return caps;
}

void GLES2DecoderImpl::UpdateCapabilities() {
  util_.set_num_compressed_texture_formats(
      validators_->compressed_texture_format.GetValues().size());
  util_.set_num_shader_binary_formats(
      validators_->shader_binary_format.GetValues().size());
}

bool GLES2DecoderImpl::InitializeShaderTranslator() {
  TRACE_EVENT0("gpu", "GLES2DecoderImpl::InitializeShaderTranslator");

  if (!use_shader_translator_) {
    return true;
  }
  ShBuiltInResources resources;
  ShInitBuiltInResources(&resources);
  resources.MaxVertexAttribs = group_->max_vertex_attribs();
  resources.MaxVertexUniformVectors =
      group_->max_vertex_uniform_vectors();
  resources.MaxVaryingVectors = group_->max_varying_vectors();
  resources.MaxVertexTextureImageUnits =
      group_->max_vertex_texture_image_units();
  resources.MaxCombinedTextureImageUnits = group_->max_texture_units();
  resources.MaxTextureImageUnits = group_->max_texture_image_units();
  resources.MaxFragmentUniformVectors =
      group_->max_fragment_uniform_vectors();
  resources.MaxDrawBuffers = group_->max_draw_buffers();
  resources.MaxExpressionComplexity = 256;
  resources.MaxCallStackDepth = 256;

#if (ANGLE_SH_VERSION >= 110)
  GLint range[2] = { 0, 0 };
  GLint precision = 0;
  GetShaderPrecisionFormatImpl(GL_FRAGMENT_SHADER, GL_HIGH_FLOAT,
                               range, &precision);
  resources.FragmentPrecisionHigh =
      PrecisionMeetsSpecForHighpFloat(range[0], range[1], precision);
#endif

  if (force_webgl_glsl_validation_) {
    resources.OES_standard_derivatives = derivatives_explicitly_enabled_;
    resources.EXT_frag_depth = frag_depth_explicitly_enabled_;
    resources.EXT_draw_buffers = draw_buffers_explicitly_enabled_;
    if (!draw_buffers_explicitly_enabled_)
      resources.MaxDrawBuffers = 1;
  } else {
    resources.OES_standard_derivatives =
        features().oes_standard_derivatives ? 1 : 0;
    resources.ARB_texture_rectangle =
        features().arb_texture_rectangle ? 1 : 0;
    resources.OES_EGL_image_external =
        features().oes_egl_image_external ? 1 : 0;
    resources.EXT_draw_buffers =
        features().ext_draw_buffers ? 1 : 0;
    resources.EXT_frag_depth =
        features().ext_frag_depth ? 1 : 0;
  }

  ShShaderSpec shader_spec = force_webgl_glsl_validation_ ? SH_WEBGL_SPEC
                                                          : SH_GLES2_SPEC;
  if (shader_spec == SH_WEBGL_SPEC && features().enable_shader_name_hashing)
#if !defined(ANGLE_SH_VERSION) || ANGLE_SH_VERSION < 108
    resources.HashFunction = &CityHashForAngle;
#else
    resources.HashFunction = &CityHash64;
#endif
  else
    resources.HashFunction = NULL;
  ShaderTranslatorInterface::GlslImplementationType implementation_type =
      gfx::GetGLImplementation() == gfx::kGLImplementationEGLGLES2 ?
          ShaderTranslatorInterface::kGlslES : ShaderTranslatorInterface::kGlsl;
  int driver_bug_workarounds = 0;
  if (workarounds().needs_glsl_built_in_function_emulation)
    driver_bug_workarounds |= SH_EMULATE_BUILT_IN_FUNCTIONS;
  if (workarounds().init_gl_position_in_vertex_shader)
    driver_bug_workarounds |= SH_INIT_GL_POSITION;
  if (workarounds().unfold_short_circuit_as_ternary_operation)
    driver_bug_workarounds |= SH_UNFOLD_SHORT_CIRCUIT;
  if (workarounds().init_varyings_without_static_use)
    driver_bug_workarounds |= SH_INIT_VARYINGS_WITHOUT_STATIC_USE;
  if (workarounds().unroll_for_loop_with_sampler_array_index)
    driver_bug_workarounds |= SH_UNROLL_FOR_LOOP_WITH_SAMPLER_ARRAY_INDEX;

  vertex_translator_ = shader_translator_cache()->GetTranslator(
      SH_VERTEX_SHADER,
      shader_spec,
      &resources,
      implementation_type,
      static_cast<ShCompileOptions>(driver_bug_workarounds));
  if (!vertex_translator_.get()) {
    LOG(ERROR) << "Could not initialize vertex shader translator.";
    Destroy(true);
    return false;
  }

  fragment_translator_ = shader_translator_cache()->GetTranslator(
      SH_FRAGMENT_SHADER,
      shader_spec,
      &resources,
      implementation_type,
      static_cast<ShCompileOptions>(driver_bug_workarounds));
  if (!fragment_translator_.get()) {
    LOG(ERROR) << "Could not initialize fragment shader translator.";
    Destroy(true);
    return false;
  }
  return true;
}

bool GLES2DecoderImpl::GenBuffersHelper(GLsizei n, const GLuint* client_ids) {
  for (GLsizei ii = 0; ii < n; ++ii) {
    if (GetBuffer(client_ids[ii])) {
      return false;
    }
  }
  scoped_ptr<GLuint[]> service_ids(new GLuint[n]);
  glGenBuffersARB(n, service_ids.get());
  for (GLsizei ii = 0; ii < n; ++ii) {
    CreateBuffer(client_ids[ii], service_ids[ii]);
  }
  return true;
}

bool GLES2DecoderImpl::GenFramebuffersHelper(
    GLsizei n, const GLuint* client_ids) {
  for (GLsizei ii = 0; ii < n; ++ii) {
    if (GetFramebuffer(client_ids[ii])) {
      return false;
    }
  }
  scoped_ptr<GLuint[]> service_ids(new GLuint[n]);
  glGenFramebuffersEXT(n, service_ids.get());
  for (GLsizei ii = 0; ii < n; ++ii) {
    CreateFramebuffer(client_ids[ii], service_ids[ii]);
  }
  return true;
}

bool GLES2DecoderImpl::GenRenderbuffersHelper(
    GLsizei n, const GLuint* client_ids) {
  for (GLsizei ii = 0; ii < n; ++ii) {
    if (GetRenderbuffer(client_ids[ii])) {
      return false;
    }
  }
  scoped_ptr<GLuint[]> service_ids(new GLuint[n]);
  glGenRenderbuffersEXT(n, service_ids.get());
  for (GLsizei ii = 0; ii < n; ++ii) {
    CreateRenderbuffer(client_ids[ii], service_ids[ii]);
  }
  return true;
}

bool GLES2DecoderImpl::GenTexturesHelper(GLsizei n, const GLuint* client_ids) {
  for (GLsizei ii = 0; ii < n; ++ii) {
    if (GetTexture(client_ids[ii])) {
      return false;
    }
  }
  scoped_ptr<GLuint[]> service_ids(new GLuint[n]);
  glGenTextures(n, service_ids.get());
  for (GLsizei ii = 0; ii < n; ++ii) {
    CreateTexture(client_ids[ii], service_ids[ii]);
  }
  return true;
}

void GLES2DecoderImpl::DeleteBuffersHelper(
    GLsizei n, const GLuint* client_ids) {
  for (GLsizei ii = 0; ii < n; ++ii) {
    Buffer* buffer = GetBuffer(client_ids[ii]);
    if (buffer && !buffer->IsDeleted()) {
      state_.vertex_attrib_manager->Unbind(buffer);
      if (state_.bound_array_buffer.get() == buffer) {
        state_.bound_array_buffer = NULL;
      }
      RemoveBuffer(client_ids[ii]);
    }
  }
}

void GLES2DecoderImpl::DeleteFramebuffersHelper(
    GLsizei n, const GLuint* client_ids) {
  bool supports_separate_framebuffer_binds =
     features().chromium_framebuffer_multisample;

  for (GLsizei ii = 0; ii < n; ++ii) {
    Framebuffer* framebuffer =
        GetFramebuffer(client_ids[ii]);
    if (framebuffer && !framebuffer->IsDeleted()) {
      if (framebuffer == framebuffer_state_.bound_draw_framebuffer.get()) {
        framebuffer_state_.bound_draw_framebuffer = NULL;
        framebuffer_state_.clear_state_dirty = true;
        GLenum target = supports_separate_framebuffer_binds ?
            GL_DRAW_FRAMEBUFFER_EXT : GL_FRAMEBUFFER;
        glBindFramebufferEXT(target, GetBackbufferServiceId());
      }
      if (framebuffer == framebuffer_state_.bound_read_framebuffer.get()) {
        framebuffer_state_.bound_read_framebuffer = NULL;
        GLenum target = supports_separate_framebuffer_binds ?
            GL_READ_FRAMEBUFFER_EXT : GL_FRAMEBUFFER;
        glBindFramebufferEXT(target, GetBackbufferServiceId());
      }
      OnFboChanged();
      RemoveFramebuffer(client_ids[ii]);
    }
  }
}

void GLES2DecoderImpl::DeleteRenderbuffersHelper(
    GLsizei n, const GLuint* client_ids) {
  bool supports_separate_framebuffer_binds =
     features().chromium_framebuffer_multisample;
  for (GLsizei ii = 0; ii < n; ++ii) {
    Renderbuffer* renderbuffer =
        GetRenderbuffer(client_ids[ii]);
    if (renderbuffer && !renderbuffer->IsDeleted()) {
      if (state_.bound_renderbuffer.get() == renderbuffer) {
        state_.bound_renderbuffer = NULL;
      }
      // Unbind from current framebuffers.
      if (supports_separate_framebuffer_binds) {
        if (framebuffer_state_.bound_read_framebuffer.get()) {
          framebuffer_state_.bound_read_framebuffer
              ->UnbindRenderbuffer(GL_READ_FRAMEBUFFER_EXT, renderbuffer);
        }
        if (framebuffer_state_.bound_draw_framebuffer.get()) {
          framebuffer_state_.bound_draw_framebuffer
              ->UnbindRenderbuffer(GL_DRAW_FRAMEBUFFER_EXT, renderbuffer);
        }
      } else {
        if (framebuffer_state_.bound_draw_framebuffer.get()) {
          framebuffer_state_.bound_draw_framebuffer
              ->UnbindRenderbuffer(GL_FRAMEBUFFER, renderbuffer);
        }
      }
      framebuffer_state_.clear_state_dirty = true;
      RemoveRenderbuffer(client_ids[ii]);
    }
  }
}

void GLES2DecoderImpl::DeleteTexturesHelper(
    GLsizei n, const GLuint* client_ids) {
  bool supports_separate_framebuffer_binds =
     features().chromium_framebuffer_multisample;
  for (GLsizei ii = 0; ii < n; ++ii) {
    TextureRef* texture_ref = GetTexture(client_ids[ii]);
    if (texture_ref) {
      Texture* texture = texture_ref->texture();
      if (texture->IsAttachedToFramebuffer()) {
        framebuffer_state_.clear_state_dirty = true;
      }
      // Unbind texture_ref from texture_ref units.
      for (size_t jj = 0; jj < state_.texture_units.size(); ++jj) {
        state_.texture_units[jj].Unbind(texture_ref);
      }
      // Unbind from current framebuffers.
      if (supports_separate_framebuffer_binds) {
        if (framebuffer_state_.bound_read_framebuffer.get()) {
          framebuffer_state_.bound_read_framebuffer
              ->UnbindTexture(GL_READ_FRAMEBUFFER_EXT, texture_ref);
        }
        if (framebuffer_state_.bound_draw_framebuffer.get()) {
          framebuffer_state_.bound_draw_framebuffer
              ->UnbindTexture(GL_DRAW_FRAMEBUFFER_EXT, texture_ref);
        }
      } else {
        if (framebuffer_state_.bound_draw_framebuffer.get()) {
          framebuffer_state_.bound_draw_framebuffer
              ->UnbindTexture(GL_FRAMEBUFFER, texture_ref);
        }
      }
#if defined(OS_MACOSX)
      GLuint service_id = texture->service_id();
      if (texture->target() == GL_TEXTURE_RECTANGLE_ARB) {
        ReleaseIOSurfaceForTexture(service_id);
      }
#endif
      RemoveTexture(client_ids[ii]);
    }
  }
}

// }  // anonymous namespace

bool GLES2DecoderImpl::MakeCurrent() {
  if (!context_.get())
    return false;

  if (!context_->MakeCurrent(surface_.get()) || WasContextLost()) {
    LOG(ERROR) << "  GLES2DecoderImpl: Context lost during MakeCurrent.";

    // Some D3D drivers cannot recover from device lost in the GPU process
    // sandbox. Allow a new GPU process to launch.
    if (workarounds().exit_on_context_lost) {
      LOG(ERROR) << "Exiting GPU process because some drivers cannot reset"
                 << " a D3D device in the Chrome GPU process sandbox.";
#if defined(OS_WIN)
      base::win::SetShouldCrashOnProcessDetach(false);
#endif
      exit(0);
    }

    return false;
  }

  ProcessFinishedAsyncTransfers();

  // Rebind the FBO if it was unbound by the context.
  if (workarounds().unbind_fbo_on_context_switch)
    RestoreFramebufferBindings();

  framebuffer_state_.clear_state_dirty = true;

  return true;
}

void GLES2DecoderImpl::ProcessFinishedAsyncTransfers() {
  ProcessPendingReadPixels();
  if (engine() && query_manager_.get())
    query_manager_->ProcessPendingTransferQueries();

  // TODO(epenner): Is there a better place to do this?
  // This needs to occur before we execute any batch of commands
  // from the client, as the client may have recieved an async
  // completion while issuing those commands.
  // "DidFlushStart" would be ideal if we had such a callback.
  async_pixel_transfer_manager_->BindCompletedAsyncTransfers();
}

static void RebindCurrentFramebuffer(
    GLenum target,
    Framebuffer* framebuffer,
    GLuint back_buffer_service_id) {
  GLuint framebuffer_id = framebuffer ? framebuffer->service_id() : 0;

  if (framebuffer_id == 0) {
    framebuffer_id = back_buffer_service_id;
  }

  glBindFramebufferEXT(target, framebuffer_id);
}

void GLES2DecoderImpl::RestoreCurrentFramebufferBindings() {
  framebuffer_state_.clear_state_dirty = true;

  if (!features().chromium_framebuffer_multisample) {
    RebindCurrentFramebuffer(
        GL_FRAMEBUFFER,
        framebuffer_state_.bound_draw_framebuffer.get(),
        GetBackbufferServiceId());
  } else {
    RebindCurrentFramebuffer(
        GL_READ_FRAMEBUFFER_EXT,
        framebuffer_state_.bound_read_framebuffer.get(),
        GetBackbufferServiceId());
    RebindCurrentFramebuffer(
        GL_DRAW_FRAMEBUFFER_EXT,
        framebuffer_state_.bound_draw_framebuffer.get(),
        GetBackbufferServiceId());
  }
  OnFboChanged();
}

bool GLES2DecoderImpl::CheckFramebufferValid(
    Framebuffer* framebuffer,
    GLenum target, const char* func_name) {
  if (!framebuffer) {
    if (backbuffer_needs_clear_bits_) {
      glClearColor(0, 0, 0, (GLES2Util::GetChannelsForFormat(
          offscreen_target_color_format_) & 0x0008) != 0 ? 0 : 1);
      glColorMask(GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE);
      glClearStencil(0);
      glStencilMask(-1);
      glClearDepth(1.0f);
      glDepthMask(true);
      glDisable(GL_SCISSOR_TEST);
      glClear(backbuffer_needs_clear_bits_);
      backbuffer_needs_clear_bits_ = 0;
      RestoreClearState();
    }
    return true;
  }

  if (framebuffer_manager()->IsComplete(framebuffer)) {
    return true;
  }

  GLenum completeness = framebuffer->IsPossiblyComplete();
  if (completeness != GL_FRAMEBUFFER_COMPLETE) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_FRAMEBUFFER_OPERATION, func_name, "framebuffer incomplete");
    return false;
  }

  // Are all the attachments cleared?
  if (renderbuffer_manager()->HaveUnclearedRenderbuffers() ||
      texture_manager()->HaveUnclearedMips()) {
    if (!framebuffer->IsCleared()) {
      // Can we clear them?
      if (framebuffer->GetStatus(texture_manager(), target) !=
          GL_FRAMEBUFFER_COMPLETE) {
        LOCAL_SET_GL_ERROR(
            GL_INVALID_FRAMEBUFFER_OPERATION, func_name,
            "framebuffer incomplete (clear)");
        return false;
      }
      ClearUnclearedAttachments(target, framebuffer);
    }
  }

  if (!framebuffer_manager()->IsComplete(framebuffer)) {
    if (framebuffer->GetStatus(texture_manager(), target) !=
        GL_FRAMEBUFFER_COMPLETE) {
      LOCAL_SET_GL_ERROR(
          GL_INVALID_FRAMEBUFFER_OPERATION, func_name,
          "framebuffer incomplete (check)");
      return false;
    }
    framebuffer_manager()->MarkAsComplete(framebuffer);
  }

  // NOTE: At this point we don't know if the framebuffer is complete but
  // we DO know that everything that needs to be cleared has been cleared.
  return true;
}

bool GLES2DecoderImpl::CheckBoundFramebuffersValid(const char* func_name) {
  if (!features().chromium_framebuffer_multisample) {
    bool valid = CheckFramebufferValid(
        framebuffer_state_.bound_draw_framebuffer.get(), GL_FRAMEBUFFER_EXT,
        func_name);

    if (valid)
      OnUseFramebuffer();

    return valid;
  }
  return CheckFramebufferValid(framebuffer_state_.bound_draw_framebuffer.get(),
                               GL_DRAW_FRAMEBUFFER_EXT,
                               func_name) &&
         CheckFramebufferValid(framebuffer_state_.bound_read_framebuffer.get(),
                               GL_READ_FRAMEBUFFER_EXT,
                               func_name);
}

gfx::Size GLES2DecoderImpl::GetBoundReadFrameBufferSize() {
  Framebuffer* framebuffer =
      GetFramebufferInfoForTarget(GL_READ_FRAMEBUFFER_EXT);
  if (framebuffer != NULL) {
    const Framebuffer::Attachment* attachment =
        framebuffer->GetAttachment(GL_COLOR_ATTACHMENT0);
    if (attachment) {
      return gfx::Size(attachment->width(), attachment->height());
    }
    return gfx::Size(0, 0);
  } else if (offscreen_target_frame_buffer_.get()) {
    return offscreen_size_;
  } else {
    return surface_->GetSize();
  }
}

GLenum GLES2DecoderImpl::GetBoundReadFrameBufferTextureType() {
  Framebuffer* framebuffer =
    GetFramebufferInfoForTarget(GL_READ_FRAMEBUFFER_EXT);
  if (framebuffer != NULL) {
    return framebuffer->GetColorAttachmentTextureType();
  } else {
    return GL_UNSIGNED_BYTE;
  }
}

GLenum GLES2DecoderImpl::GetBoundReadFrameBufferInternalFormat() {
  Framebuffer* framebuffer =
      GetFramebufferInfoForTarget(GL_READ_FRAMEBUFFER_EXT);
  if (framebuffer != NULL) {
    return framebuffer->GetColorAttachmentFormat();
  } else if (offscreen_target_frame_buffer_.get()) {
    return offscreen_target_color_format_;
  } else {
    return back_buffer_color_format_;
  }
}

GLenum GLES2DecoderImpl::GetBoundDrawFrameBufferInternalFormat() {
  Framebuffer* framebuffer =
      GetFramebufferInfoForTarget(GL_DRAW_FRAMEBUFFER_EXT);
  if (framebuffer != NULL) {
    return framebuffer->GetColorAttachmentFormat();
  } else if (offscreen_target_frame_buffer_.get()) {
    return offscreen_target_color_format_;
  } else {
    return back_buffer_color_format_;
  }
}

void GLES2DecoderImpl::UpdateParentTextureInfo() {
  if (!offscreen_saved_color_texture_info_.get())
    return;
  GLenum target = offscreen_saved_color_texture_info_->texture()->target();
  glBindTexture(target, offscreen_saved_color_texture_info_->service_id());
  texture_manager()->SetLevelInfo(
      offscreen_saved_color_texture_info_.get(),
      GL_TEXTURE_2D,
      0,  // level
      GL_RGBA,
      offscreen_size_.width(),
      offscreen_size_.height(),
      1,  // depth
      0,  // border
      GL_RGBA,
      GL_UNSIGNED_BYTE,
      true);
  texture_manager()->SetParameteri(
      "UpdateParentTextureInfo",
      GetErrorState(),
      offscreen_saved_color_texture_info_.get(),
      GL_TEXTURE_MAG_FILTER,
      GL_NEAREST);
  texture_manager()->SetParameteri(
      "UpdateParentTextureInfo",
      GetErrorState(),
      offscreen_saved_color_texture_info_.get(),
      GL_TEXTURE_MIN_FILTER,
      GL_NEAREST);
  texture_manager()->SetParameteri(
      "UpdateParentTextureInfo",
      GetErrorState(),
      offscreen_saved_color_texture_info_.get(),
      GL_TEXTURE_WRAP_S,
      GL_CLAMP_TO_EDGE);
  texture_manager()->SetParameteri(
      "UpdateParentTextureInfo",
      GetErrorState(),
      offscreen_saved_color_texture_info_.get(),
      GL_TEXTURE_WRAP_T,
      GL_CLAMP_TO_EDGE);
  TextureRef* texture_ref = texture_manager()->GetTextureInfoForTarget(
      &state_, target);
  glBindTexture(target, texture_ref ? texture_ref->service_id() : 0);
}

void GLES2DecoderImpl::SetResizeCallback(
    const base::Callback<void(gfx::Size, float)>& callback) {
  resize_callback_ = callback;
}

Logger* GLES2DecoderImpl::GetLogger() {
  return &logger_;
}

void GLES2DecoderImpl::BeginDecoding() {
  gpu_tracer_->BeginDecoding();
  gpu_trace_commands_ = gpu_tracer_->IsTracing();
}

void GLES2DecoderImpl::EndDecoding() {
  gpu_tracer_->EndDecoding();
}

ErrorState* GLES2DecoderImpl::GetErrorState() {
  return state_.GetErrorState();
}

void GLES2DecoderImpl::SetShaderCacheCallback(
    const ShaderCacheCallback& callback) {
  shader_cache_callback_ = callback;
}

void GLES2DecoderImpl::SetWaitSyncPointCallback(
    const WaitSyncPointCallback& callback) {
  wait_sync_point_callback_ = callback;
}

AsyncPixelTransferManager*
    GLES2DecoderImpl::GetAsyncPixelTransferManager() {
  return async_pixel_transfer_manager_.get();
}

void GLES2DecoderImpl::ResetAsyncPixelTransferManagerForTest() {
  async_pixel_transfer_manager_.reset();
}

void GLES2DecoderImpl::SetAsyncPixelTransferManagerForTest(
    AsyncPixelTransferManager* manager) {
  async_pixel_transfer_manager_ = make_scoped_ptr(manager);
}

bool GLES2DecoderImpl::GetServiceTextureId(uint32 client_texture_id,
                                           uint32* service_texture_id) {
  TextureRef* texture_ref = texture_manager()->GetTexture(client_texture_id);
  if (texture_ref) {
    *service_texture_id = texture_ref->service_id();
    return true;
  }
  return false;
}

uint32 GLES2DecoderImpl::GetTextureUploadCount() {
  return texture_state_.texture_upload_count +
         async_pixel_transfer_manager_->GetTextureUploadCount();
}

base::TimeDelta GLES2DecoderImpl::GetTotalTextureUploadTime() {
  return texture_state_.total_texture_upload_time +
         async_pixel_transfer_manager_->GetTotalTextureUploadTime();
}

base::TimeDelta GLES2DecoderImpl::GetTotalProcessingCommandsTime() {
  return total_processing_commands_time_;
}

void GLES2DecoderImpl::AddProcessingCommandsTime(base::TimeDelta time) {
  total_processing_commands_time_ += time;
}

void GLES2DecoderImpl::Destroy(bool have_context) {
  if (!initialized())
    return;

  DCHECK(!have_context || context_->IsCurrent(NULL));

  // Unbind everything.
  state_.vertex_attrib_manager = NULL;
  default_vertex_attrib_manager_ = NULL;
  state_.texture_units.clear();
  state_.bound_array_buffer = NULL;
  state_.current_queries.clear();
  framebuffer_state_.bound_read_framebuffer = NULL;
  framebuffer_state_.bound_draw_framebuffer = NULL;
  state_.bound_renderbuffer = NULL;

  if (offscreen_saved_color_texture_info_.get()) {
    DCHECK(offscreen_target_color_texture_);
    DCHECK_EQ(offscreen_saved_color_texture_info_->service_id(),
              offscreen_saved_color_texture_->id());
    offscreen_saved_color_texture_->Invalidate();
    offscreen_saved_color_texture_info_ = NULL;
  }
  if (have_context) {
    if (copy_texture_CHROMIUM_.get()) {
      copy_texture_CHROMIUM_->Destroy();
      copy_texture_CHROMIUM_.reset();
    }

    if (state_.current_program.get()) {
      program_manager()->UnuseProgram(shader_manager(),
                                      state_.current_program.get());
    }

    if (attrib_0_buffer_id_) {
      glDeleteBuffersARB(1, &attrib_0_buffer_id_);
    }
    if (fixed_attrib_buffer_id_) {
      glDeleteBuffersARB(1, &fixed_attrib_buffer_id_);
    }

    if (validation_texture_) {
      glDeleteTextures(1, &validation_texture_);
      glDeleteFramebuffersEXT(1, &validation_fbo_multisample_);
      glDeleteFramebuffersEXT(1, &validation_fbo_);
    }

    if (offscreen_target_frame_buffer_.get())
      offscreen_target_frame_buffer_->Destroy();
    if (offscreen_target_color_texture_.get())
      offscreen_target_color_texture_->Destroy();
    if (offscreen_target_color_render_buffer_.get())
      offscreen_target_color_render_buffer_->Destroy();
    if (offscreen_target_depth_render_buffer_.get())
      offscreen_target_depth_render_buffer_->Destroy();
    if (offscreen_target_stencil_render_buffer_.get())
      offscreen_target_stencil_render_buffer_->Destroy();
    if (offscreen_saved_frame_buffer_.get())
      offscreen_saved_frame_buffer_->Destroy();
    if (offscreen_saved_color_texture_.get())
      offscreen_saved_color_texture_->Destroy();
    if (offscreen_resolved_frame_buffer_.get())
      offscreen_resolved_frame_buffer_->Destroy();
    if (offscreen_resolved_color_texture_.get())
      offscreen_resolved_color_texture_->Destroy();
  } else {
    if (offscreen_target_frame_buffer_.get())
      offscreen_target_frame_buffer_->Invalidate();
    if (offscreen_target_color_texture_.get())
      offscreen_target_color_texture_->Invalidate();
    if (offscreen_target_color_render_buffer_.get())
      offscreen_target_color_render_buffer_->Invalidate();
    if (offscreen_target_depth_render_buffer_.get())
      offscreen_target_depth_render_buffer_->Invalidate();
    if (offscreen_target_stencil_render_buffer_.get())
      offscreen_target_stencil_render_buffer_->Invalidate();
    if (offscreen_saved_frame_buffer_.get())
      offscreen_saved_frame_buffer_->Invalidate();
    if (offscreen_saved_color_texture_.get())
      offscreen_saved_color_texture_->Invalidate();
    if (offscreen_resolved_frame_buffer_.get())
      offscreen_resolved_frame_buffer_->Invalidate();
    if (offscreen_resolved_color_texture_.get())
      offscreen_resolved_color_texture_->Invalidate();
  }

  // Current program must be cleared after calling ProgramManager::UnuseProgram.
  // Otherwise, we can leak objects. http://crbug.com/258772.
  // state_.current_program must be reset before group_ is reset because
  // the later deletes the ProgramManager object that referred by
  // state_.current_program object.
  state_.current_program = NULL;

  copy_texture_CHROMIUM_.reset();

  if (query_manager_.get()) {
    query_manager_->Destroy(have_context);
    query_manager_.reset();
  }

  if (vertex_array_manager_ .get()) {
    vertex_array_manager_->Destroy(have_context);
    vertex_array_manager_.reset();
  }

  offscreen_target_frame_buffer_.reset();
  offscreen_target_color_texture_.reset();
  offscreen_target_color_render_buffer_.reset();
  offscreen_target_depth_render_buffer_.reset();
  offscreen_target_stencil_render_buffer_.reset();
  offscreen_saved_frame_buffer_.reset();
  offscreen_saved_color_texture_.reset();
  offscreen_resolved_frame_buffer_.reset();
  offscreen_resolved_color_texture_.reset();

  // Need to release these before releasing |group_| which may own the
  // ShaderTranslatorCache.
  fragment_translator_ = NULL;
  vertex_translator_ = NULL;

  // Should destroy the transfer manager before the texture manager held
  // by the context group.
  async_pixel_transfer_manager_.reset();

  if (group_.get()) {
    framebuffer_manager()->RemoveObserver(this);
    group_->Destroy(this, have_context);
    group_ = NULL;
  }

  if (context_.get()) {
    context_->ReleaseCurrent(NULL);
    context_ = NULL;
  }

#if defined(OS_MACOSX)
  for (TextureToIOSurfaceMap::iterator it = texture_to_io_surface_map_.begin();
       it != texture_to_io_surface_map_.end(); ++it) {
    CFRelease(it->second);
  }
  texture_to_io_surface_map_.clear();
#endif
}

void GLES2DecoderImpl::SetSurface(
    const scoped_refptr<gfx::GLSurface>& surface) {
  DCHECK(context_->IsCurrent(NULL));
  DCHECK(surface_.get());
  surface_ = surface;
  RestoreCurrentFramebufferBindings();
}

void GLES2DecoderImpl::ProduceFrontBuffer(const Mailbox& mailbox) {
  if (!offscreen_saved_color_texture_.get()) {
    LOG(ERROR) << "Called ProduceFrontBuffer on a non-offscreen context";
    return;
  }
  if (!offscreen_saved_color_texture_info_.get()) {
    GLuint service_id = offscreen_saved_color_texture_->id();
    offscreen_saved_color_texture_info_ = TextureRef::Create(
        texture_manager(), 0, service_id);
    texture_manager()->SetTarget(offscreen_saved_color_texture_info_.get(),
                                 GL_TEXTURE_2D);
    UpdateParentTextureInfo();
  }
  mailbox_manager()->ProduceTexture(
      GL_TEXTURE_2D, mailbox, offscreen_saved_color_texture_info_->texture());
}

bool GLES2DecoderImpl::ResizeOffscreenFrameBuffer(const gfx::Size& size) {
  bool is_offscreen = !!offscreen_target_frame_buffer_.get();
  if (!is_offscreen) {
    LOG(ERROR) << "GLES2DecoderImpl::ResizeOffscreenFrameBuffer called "
               << " with an onscreen framebuffer.";
    return false;
  }

  if (offscreen_size_ == size)
    return true;

  offscreen_size_ = size;
  int w = offscreen_size_.width();
  int h = offscreen_size_.height();
  if (w < 0 || h < 0 || h >= (INT_MAX / 4) / (w ? w : 1)) {
    LOG(ERROR) << "GLES2DecoderImpl::ResizeOffscreenFrameBuffer failed "
               << "to allocate storage due to excessive dimensions.";
    return false;
  }

  // Reallocate the offscreen target buffers.
  DCHECK(offscreen_target_color_format_);
  if (IsOffscreenBufferMultisampled()) {
    if (!offscreen_target_color_render_buffer_->AllocateStorage(
        feature_info_, offscreen_size_, offscreen_target_color_format_,
        offscreen_target_samples_)) {
      LOG(ERROR) << "GLES2DecoderImpl::ResizeOffscreenFrameBuffer failed "
                 << "to allocate storage for offscreen target color buffer.";
      return false;
    }
  } else {
    if (!offscreen_target_color_texture_->AllocateStorage(
        offscreen_size_, offscreen_target_color_format_, false)) {
      LOG(ERROR) << "GLES2DecoderImpl::ResizeOffscreenFrameBuffer failed "
                 << "to allocate storage for offscreen target color texture.";
      return false;
    }
  }
  if (offscreen_target_depth_format_ &&
      !offscreen_target_depth_render_buffer_->AllocateStorage(
      feature_info_, offscreen_size_, offscreen_target_depth_format_,
      offscreen_target_samples_)) {
    LOG(ERROR) << "GLES2DecoderImpl::ResizeOffscreenFrameBuffer failed "
               << "to allocate storage for offscreen target depth buffer.";
    return false;
  }
  if (offscreen_target_stencil_format_ &&
      !offscreen_target_stencil_render_buffer_->AllocateStorage(
      feature_info_, offscreen_size_, offscreen_target_stencil_format_,
      offscreen_target_samples_)) {
    LOG(ERROR) << "GLES2DecoderImpl::ResizeOffscreenFrameBuffer failed "
               << "to allocate storage for offscreen target stencil buffer.";
    return false;
  }

  // Attach the offscreen target buffers to the target frame buffer.
  if (IsOffscreenBufferMultisampled()) {
    offscreen_target_frame_buffer_->AttachRenderBuffer(
        GL_COLOR_ATTACHMENT0,
        offscreen_target_color_render_buffer_.get());
  } else {
    offscreen_target_frame_buffer_->AttachRenderTexture(
        offscreen_target_color_texture_.get());
  }
  if (offscreen_target_depth_format_) {
    offscreen_target_frame_buffer_->AttachRenderBuffer(
        GL_DEPTH_ATTACHMENT,
        offscreen_target_depth_render_buffer_.get());
  }
  const bool packed_depth_stencil =
      offscreen_target_depth_format_ == GL_DEPTH24_STENCIL8;
  if (packed_depth_stencil) {
    offscreen_target_frame_buffer_->AttachRenderBuffer(
        GL_STENCIL_ATTACHMENT,
        offscreen_target_depth_render_buffer_.get());
  } else if (offscreen_target_stencil_format_) {
    offscreen_target_frame_buffer_->AttachRenderBuffer(
        GL_STENCIL_ATTACHMENT,
        offscreen_target_stencil_render_buffer_.get());
  }

  if (offscreen_target_frame_buffer_->CheckStatus() !=
      GL_FRAMEBUFFER_COMPLETE) {
      LOG(ERROR) << "GLES2DecoderImpl::ResizeOffscreenFrameBuffer failed "
                 << "because offscreen FBO was incomplete.";
    return false;
  }

  // Clear the target frame buffer.
  {
    ScopedFrameBufferBinder binder(this, offscreen_target_frame_buffer_->id());
    glClearColor(0, 0, 0, (GLES2Util::GetChannelsForFormat(
        offscreen_target_color_format_) & 0x0008) != 0 ? 0 : 1);
    glColorMask(GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE);
    glClearStencil(0);
    glStencilMaskSeparate(GL_FRONT, -1);
    glStencilMaskSeparate(GL_BACK, -1);
    glClearDepth(0);
    glDepthMask(GL_TRUE);
    glDisable(GL_SCISSOR_TEST);
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);
    RestoreClearState();
  }

  // Destroy the offscreen resolved framebuffers.
  if (offscreen_resolved_frame_buffer_.get())
    offscreen_resolved_frame_buffer_->Destroy();
  if (offscreen_resolved_color_texture_.get())
    offscreen_resolved_color_texture_->Destroy();
  offscreen_resolved_color_texture_.reset();
  offscreen_resolved_frame_buffer_.reset();

  return true;
}

error::Error GLES2DecoderImpl::HandleResizeCHROMIUM(
    uint32 immediate_data_size, const cmds::ResizeCHROMIUM& c) {
  if (!offscreen_target_frame_buffer_.get() && surface_->DeferDraws())
    return error::kDeferCommandUntilLater;

  GLuint width = static_cast<GLuint>(c.width);
  GLuint height = static_cast<GLuint>(c.height);
  GLfloat scale_factor = c.scale_factor;
  TRACE_EVENT2("gpu", "glResizeChromium", "width", width, "height", height);

  width = std::max(1U, width);
  height = std::max(1U, height);

#if defined(OS_POSIX) && !defined(OS_MACOSX) && \
    !defined(UI_COMPOSITOR_IMAGE_TRANSPORT)
  // Make sure that we are done drawing to the back buffer before resizing.
  glFinish();
#endif
  bool is_offscreen = !!offscreen_target_frame_buffer_.get();
  if (is_offscreen) {
    if (!ResizeOffscreenFrameBuffer(gfx::Size(width, height))) {
      LOG(ERROR) << "GLES2DecoderImpl: Context lost because "
                 << "ResizeOffscreenFrameBuffer failed.";
      return error::kLostContext;
    }
  }

  if (!resize_callback_.is_null()) {
    resize_callback_.Run(gfx::Size(width, height), scale_factor);
    DCHECK(context_->IsCurrent(surface_.get()));
    if (!context_->IsCurrent(surface_.get())) {
      LOG(ERROR) << "GLES2DecoderImpl: Context lost because context no longer "
                 << "current after resize callback.";
      return error::kLostContext;
    }
  }

  return error::kNoError;
}

const char* GLES2DecoderImpl::GetCommandName(unsigned int command_id) const {
  if (command_id > kStartPoint && command_id < kNumCommands) {
    return gles2::GetCommandName(static_cast<CommandId>(command_id));
  }
  return GetCommonCommandName(static_cast<cmd::CommandId>(command_id));
}

// Decode command with its arguments, and call the corresponding GL function.
// Note: args is a pointer to the command buffer. As such, it could be changed
// by a (malicious) client at any time, so if validation has to happen, it
// should operate on a copy of them.
error::Error GLES2DecoderImpl::DoCommand(
    unsigned int command,
    unsigned int arg_count,
    const void* cmd_data) {
  error::Error result = error::kNoError;
  if (log_commands()) {
    // TODO(notme): Change this to a LOG/VLOG that works in release. Tried
    // VLOG(1), no luck.
    LOG(ERROR) << "[" << logger_.GetLogPrefix() << "]" << "cmd: "
               << GetCommandName(command);
  }
  unsigned int command_index = command - kStartPoint - 1;
  if (command_index < arraysize(g_command_info)) {
    const CommandInfo& info = g_command_info[command_index];
    unsigned int info_arg_count = static_cast<unsigned int>(info.arg_count);
    if ((info.arg_flags == cmd::kFixed && arg_count == info_arg_count) ||
        (info.arg_flags == cmd::kAtLeastN && arg_count >= info_arg_count)) {
      bool doing_gpu_trace = false;
      if (gpu_trace_commands_) {
        if (CMD_FLAG_GET_TRACE_LEVEL(info.cmd_flags) <= gpu_trace_level_) {
          doing_gpu_trace = true;
          gpu_tracer_->Begin(GetCommandName(command), kTraceDecoder);
        }
      }

      uint32 immediate_data_size =
          (arg_count - info_arg_count) * sizeof(CommandBufferEntry);  // NOLINT
      switch (command) {
        #define GLES2_CMD_OP(name)                                 \
          case cmds::name::kCmdId:                                 \
            result = Handle ## name(                               \
                immediate_data_size,                               \
                *static_cast<const gles2::cmds::name*>(cmd_data)); \
            break;                                                 \

        GLES2_COMMAND_LIST(GLES2_CMD_OP)
        #undef GLES2_CMD_OP
      }

      if (doing_gpu_trace)
        gpu_tracer_->End(kTraceDecoder);

      if (debug()) {
        GLenum error;
        while ((error = glGetError()) != GL_NO_ERROR) {
          LOG(ERROR) << "[" << logger_.GetLogPrefix() << "] "
                     << "GL ERROR: " << GLES2Util::GetStringEnum(error) << " : "
                     << GetCommandName(command);
          LOCAL_SET_GL_ERROR(error, "DoCommand", "GL error from driver");
        }
      }
    } else {
      result = error::kInvalidArguments;
    }
  } else {
    result = DoCommonCommand(command, arg_count, cmd_data);
  }
  if (result == error::kNoError && current_decoder_error_ != error::kNoError) {
      result = current_decoder_error_;
      current_decoder_error_ = error::kNoError;
  }
  return result;
}

void GLES2DecoderImpl::RemoveBuffer(GLuint client_id) {
  buffer_manager()->RemoveBuffer(client_id);
}

bool GLES2DecoderImpl::CreateProgramHelper(GLuint client_id) {
  if (GetProgram(client_id)) {
    return false;
  }
  GLuint service_id = glCreateProgram();
  if (service_id != 0) {
    CreateProgram(client_id, service_id);
  }
  return true;
}

bool GLES2DecoderImpl::CreateShaderHelper(GLenum type, GLuint client_id) {
  if (GetShader(client_id)) {
    return false;
  }
  GLuint service_id = glCreateShader(type);
  if (service_id != 0) {
    CreateShader(client_id, service_id, type);
  }
  return true;
}

void GLES2DecoderImpl::DoFinish() {
  glFinish();
  ProcessPendingReadPixels();
  ProcessPendingQueries();
}

void GLES2DecoderImpl::DoFlush() {
  glFlush();
  ProcessPendingQueries();
}

void GLES2DecoderImpl::DoActiveTexture(GLenum texture_unit) {
  GLuint texture_index = texture_unit - GL_TEXTURE0;
  if (texture_index >= state_.texture_units.size()) {
    LOCAL_SET_GL_ERROR_INVALID_ENUM(
        "glActiveTexture", texture_unit, "texture_unit");
    return;
  }
  state_.active_texture_unit = texture_index;
  glActiveTexture(texture_unit);
}

void GLES2DecoderImpl::DoBindBuffer(GLenum target, GLuint client_id) {
  Buffer* buffer = NULL;
  GLuint service_id = 0;
  if (client_id != 0) {
    buffer = GetBuffer(client_id);
    if (!buffer) {
      if (!group_->bind_generates_resource()) {
        LOCAL_SET_GL_ERROR(GL_INVALID_OPERATION,
                           "glBindBuffer",
                           "id not generated by glGenBuffers");
        return;
      }

      // It's a new id so make a buffer buffer for it.
      glGenBuffersARB(1, &service_id);
      CreateBuffer(client_id, service_id);
      buffer = GetBuffer(client_id);
      IdAllocatorInterface* id_allocator =
          group_->GetIdAllocator(id_namespaces::kBuffers);
      id_allocator->MarkAsUsed(client_id);
    }
  }
  LogClientServiceForInfo(buffer, client_id, "glBindBuffer");
  if (buffer) {
    if (!buffer_manager()->SetTarget(buffer, target)) {
      LOCAL_SET_GL_ERROR(
          GL_INVALID_OPERATION,
          "glBindBuffer", "buffer bound to more than 1 target");
      return;
    }
    service_id = buffer->service_id();
  }
  switch (target) {
    case GL_ARRAY_BUFFER:
      state_.bound_array_buffer = buffer;
      break;
    case GL_ELEMENT_ARRAY_BUFFER:
      state_.vertex_attrib_manager->SetElementArrayBuffer(buffer);
      break;
    default:
      NOTREACHED();  // Validation should prevent us getting here.
      break;
  }
  glBindBuffer(target, service_id);
}

bool GLES2DecoderImpl::BoundFramebufferHasColorAttachmentWithAlpha(
    bool all_draw_buffers) {
  Framebuffer* framebuffer =
      GetFramebufferInfoForTarget(GL_DRAW_FRAMEBUFFER_EXT);
  if (!all_draw_buffers || !framebuffer) {
    return (GLES2Util::GetChannelsForFormat(
        GetBoundDrawFrameBufferInternalFormat()) & 0x0008) != 0;
  }
  return framebuffer->HasAlphaMRT();
}

bool GLES2DecoderImpl::BoundFramebufferHasDepthAttachment() {
  Framebuffer* framebuffer =
      GetFramebufferInfoForTarget(GL_DRAW_FRAMEBUFFER_EXT);
  if (framebuffer) {
    return framebuffer->HasDepthAttachment();
  }
  if (offscreen_target_frame_buffer_.get()) {
    return offscreen_target_depth_format_ != 0;
  }
  return back_buffer_has_depth_;
}

bool GLES2DecoderImpl::BoundFramebufferHasStencilAttachment() {
  Framebuffer* framebuffer =
      GetFramebufferInfoForTarget(GL_DRAW_FRAMEBUFFER_EXT);
  if (framebuffer) {
    return framebuffer->HasStencilAttachment();
  }
  if (offscreen_target_frame_buffer_.get()) {
    return offscreen_target_stencil_format_ != 0 ||
           offscreen_target_depth_format_ == GL_DEPTH24_STENCIL8;
  }
  return back_buffer_has_stencil_;
}

void GLES2DecoderImpl::ApplyDirtyState() {
  if (framebuffer_state_.clear_state_dirty) {
    glColorMask(
        state_.color_mask_red, state_.color_mask_green, state_.color_mask_blue,
        state_.color_mask_alpha &&
            BoundFramebufferHasColorAttachmentWithAlpha(true));
    bool have_depth = BoundFramebufferHasDepthAttachment();
    glDepthMask(state_.depth_mask && have_depth);
    EnableDisable(GL_DEPTH_TEST, state_.enable_flags.depth_test && have_depth);
    bool have_stencil = BoundFramebufferHasStencilAttachment();
    glStencilMaskSeparate(
        GL_FRONT, have_stencil ? state_.stencil_front_writemask : 0);
    glStencilMaskSeparate(
        GL_BACK, have_stencil ? state_.stencil_back_writemask : 0);
    EnableDisable(
        GL_STENCIL_TEST, state_.enable_flags.stencil_test && have_stencil);
    EnableDisable(GL_CULL_FACE, state_.enable_flags.cull_face);
    EnableDisable(GL_SCISSOR_TEST, state_.enable_flags.scissor_test);
    EnableDisable(GL_BLEND, state_.enable_flags.blend);
    framebuffer_state_.clear_state_dirty = false;
  }
}

GLuint GLES2DecoderImpl::GetBackbufferServiceId() const {
  return (offscreen_target_frame_buffer_.get())
             ? offscreen_target_frame_buffer_->id()
             : (surface_.get() ? surface_->GetBackingFrameBufferObject() : 0);
}

void GLES2DecoderImpl::RestoreState(const ContextState* prev_state) const {
  TRACE_EVENT1("gpu", "GLES2DecoderImpl::RestoreState",
               "context", logger_.GetLogPrefix());
  // Restore the Framebuffer first because of bugs in Intel drivers.
  // Intel drivers incorrectly clip the viewport settings to
  // the size of the current framebuffer object.
  RestoreFramebufferBindings();
  state_.RestoreState(prev_state);
}

void GLES2DecoderImpl::RestoreFramebufferBindings() const {
  GLuint service_id =
      framebuffer_state_.bound_draw_framebuffer.get()
          ? framebuffer_state_.bound_draw_framebuffer->service_id()
          : GetBackbufferServiceId();
  if (!features().chromium_framebuffer_multisample) {
    glBindFramebufferEXT(GL_FRAMEBUFFER, service_id);
  } else {
    glBindFramebufferEXT(GL_DRAW_FRAMEBUFFER, service_id);
    service_id = framebuffer_state_.bound_read_framebuffer.get()
                     ? framebuffer_state_.bound_read_framebuffer->service_id()
                     : GetBackbufferServiceId();
    glBindFramebufferEXT(GL_READ_FRAMEBUFFER, service_id);
  }
  OnFboChanged();
}

void GLES2DecoderImpl::RestoreTextureState(unsigned service_id) const {
  Texture* texture = texture_manager()->GetTextureForServiceId(service_id);
  if (texture) {
    GLenum target = texture->target();
    glBindTexture(target, service_id);
    glTexParameteri(
        target, GL_TEXTURE_WRAP_S, texture->wrap_s());
    glTexParameteri(
        target, GL_TEXTURE_WRAP_T, texture->wrap_t());
    glTexParameteri(
        target, GL_TEXTURE_MIN_FILTER, texture->min_filter());
    glTexParameteri(
        target, GL_TEXTURE_MAG_FILTER, texture->mag_filter());
    RestoreTextureUnitBindings(state_.active_texture_unit);
  }
}

void GLES2DecoderImpl::ClearAllAttributes() const {
  for (uint32 i = 0; i < group_->max_vertex_attribs(); ++i) {
    if (i != 0) // Never disable attribute 0
      glDisableVertexAttribArray(i);
    if(features().angle_instanced_arrays)
      glVertexAttribDivisorANGLE(i, 0);
  }
}

void GLES2DecoderImpl::RestoreAllAttributes() const {
  for (uint32 i = 0; i < group_->max_vertex_attribs(); ++i)
    RestoreAttribute(i);
}

void GLES2DecoderImpl::OnFboChanged() const {
  if (workarounds().restore_scissor_on_fbo_change)
    state_.fbo_binding_for_scissor_workaround_dirty_ = true;
}

// Called after the FBO is checked for completeness.
void GLES2DecoderImpl::OnUseFramebuffer() const {
  if (state_.fbo_binding_for_scissor_workaround_dirty_) {
    state_.fbo_binding_for_scissor_workaround_dirty_ = false;
    // The driver forgets the correct scissor when modifying the FBO binding.
    glScissor(state_.scissor_x,
              state_.scissor_y,
              state_.scissor_width,
              state_.scissor_height);

    // crbug.com/222018 - Also on QualComm, the flush here avoids flicker,
    // it's unclear how this bug works.
    glFlush();
  }
}

void GLES2DecoderImpl::DoBindFramebuffer(GLenum target, GLuint client_id) {
  Framebuffer* framebuffer = NULL;
  GLuint service_id = 0;
  if (client_id != 0) {
    framebuffer = GetFramebuffer(client_id);
    if (!framebuffer) {
      if (!group_->bind_generates_resource()) {
        LOCAL_SET_GL_ERROR(GL_INVALID_OPERATION,
                           "glBindFramebuffer",
                           "id not generated by glGenFramebuffers");
        return;
      }

      // It's a new id so make a framebuffer framebuffer for it.
      glGenFramebuffersEXT(1, &service_id);
      CreateFramebuffer(client_id, service_id);
      framebuffer = GetFramebuffer(client_id);
      IdAllocatorInterface* id_allocator =
          group_->GetIdAllocator(id_namespaces::kFramebuffers);
      id_allocator->MarkAsUsed(client_id);
    } else {
      service_id = framebuffer->service_id();
    }
    framebuffer->MarkAsValid();
  }
  LogClientServiceForInfo(framebuffer, client_id, "glBindFramebuffer");

  if (target == GL_FRAMEBUFFER || target == GL_DRAW_FRAMEBUFFER_EXT) {
    framebuffer_state_.bound_draw_framebuffer = framebuffer;
  }

  // vmiura: This looks like dup code
  if (target == GL_FRAMEBUFFER || target == GL_READ_FRAMEBUFFER_EXT) {
    framebuffer_state_.bound_read_framebuffer = framebuffer;
  }

  framebuffer_state_.clear_state_dirty = true;

  // If we are rendering to the backbuffer get the FBO id for any simulated
  // backbuffer.
  if (framebuffer == NULL) {
    service_id = GetBackbufferServiceId();
  }

  glBindFramebufferEXT(target, service_id);
  OnFboChanged();
}

void GLES2DecoderImpl::DoBindRenderbuffer(GLenum target, GLuint client_id) {
  Renderbuffer* renderbuffer = NULL;
  GLuint service_id = 0;
  if (client_id != 0) {
    renderbuffer = GetRenderbuffer(client_id);
    if (!renderbuffer) {
      if (!group_->bind_generates_resource()) {
        LOCAL_SET_GL_ERROR(GL_INVALID_OPERATION,
                           "glBindRenderbuffer",
                           "id not generated by glGenRenderbuffers");
        return;
      }

      // It's a new id so make a renderbuffer renderbuffer for it.
      glGenRenderbuffersEXT(1, &service_id);
      CreateRenderbuffer(client_id, service_id);
      renderbuffer = GetRenderbuffer(client_id);
      IdAllocatorInterface* id_allocator =
          group_->GetIdAllocator(id_namespaces::kRenderbuffers);
      id_allocator->MarkAsUsed(client_id);
    } else {
      service_id = renderbuffer->service_id();
    }
    renderbuffer->MarkAsValid();
  }
  LogClientServiceForInfo(renderbuffer, client_id, "glBindRenderbuffer");
  state_.bound_renderbuffer = renderbuffer;
  glBindRenderbufferEXT(target, service_id);
}

void GLES2DecoderImpl::DoBindTexture(GLenum target, GLuint client_id) {
  TextureRef* texture_ref = NULL;
  GLuint service_id = 0;
  if (client_id != 0) {
    texture_ref = GetTexture(client_id);
    if (!texture_ref) {
      if (!group_->bind_generates_resource()) {
        LOCAL_SET_GL_ERROR(GL_INVALID_OPERATION,
                           "glBindTexture",
                           "id not generated by glGenTextures");
        return;
      }

      // It's a new id so make a texture texture for it.
      glGenTextures(1, &service_id);
      DCHECK_NE(0u, service_id);
      CreateTexture(client_id, service_id);
      texture_ref = GetTexture(client_id);
      IdAllocatorInterface* id_allocator =
          group_->GetIdAllocator(id_namespaces::kTextures);
      id_allocator->MarkAsUsed(client_id);
    }
  } else {
    texture_ref = texture_manager()->GetDefaultTextureInfo(target);
  }
  Texture* texture = texture_ref->texture();

  // Check the texture exists
  // Check that we are not trying to bind it to a different target.
  if (texture->target() != 0 && texture->target() != target) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_OPERATION,
        "glBindTexture", "texture bound to more than 1 target.");
    return;
  }
  LogClientServiceForInfo(texture, client_id, "glBindTexture");
  if (texture->target() == 0) {
    texture_manager()->SetTarget(texture_ref, target);
  }
  glBindTexture(target, texture->service_id());

  TextureUnit& unit = state_.texture_units[state_.active_texture_unit];
  unit.bind_target = target;
  switch (target) {
    case GL_TEXTURE_2D:
      unit.bound_texture_2d = texture_ref;
      break;
    case GL_TEXTURE_CUBE_MAP:
      unit.bound_texture_cube_map = texture_ref;
      break;
    case GL_TEXTURE_EXTERNAL_OES:
      unit.bound_texture_external_oes = texture_ref;
      break;
    case GL_TEXTURE_RECTANGLE_ARB:
      unit.bound_texture_rectangle_arb = texture_ref;
      break;
    default:
      NOTREACHED();  // Validation should prevent us getting here.
      break;
  }
}

void GLES2DecoderImpl::DoDisableVertexAttribArray(GLuint index) {
  if (state_.vertex_attrib_manager->Enable(index, false)) {
    if (index != 0 ||
        gfx::GetGLImplementation() == gfx::kGLImplementationEGLGLES2) {
      glDisableVertexAttribArray(index);
    }
  } else {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_VALUE,
        "glDisableVertexAttribArray", "index out of range");
  }
}

void GLES2DecoderImpl::DoDiscardFramebufferEXT(GLenum target,
                                               GLsizei numAttachments,
                                               const GLenum* attachments) {
  if (!features().ext_discard_framebuffer) {
    LOCAL_SET_GL_ERROR(GL_INVALID_OPERATION,
                       "glDiscardFramebufferEXT",
                       "function not available");
    return;
  }

  Framebuffer* framebuffer =
      GetFramebufferInfoForTarget(GL_FRAMEBUFFER);

  // Validates the attachments. If one of them fails
  // the whole command fails.
  for (GLsizei i = 0; i < numAttachments; ++i) {
    if ((framebuffer &&
        !validators_->attachment.IsValid(attachments[i])) ||
       (!framebuffer &&
        !validators_->backbuffer_attachment.IsValid(attachments[i]))) {
      LOCAL_SET_GL_ERROR_INVALID_ENUM(
          "glDiscardFramebufferEXT", attachments[i], "attachments");
      return;
    }
  }

  // Marks each one of them as not cleared
  for (GLsizei i = 0; i < numAttachments; ++i) {
    if (framebuffer) {
      framebuffer->MarkAttachmentAsCleared(renderbuffer_manager(),
                                           texture_manager(),
                                           attachments[i],
                                           false);
    } else {
      switch (attachments[i]) {
        case GL_COLOR_EXT:
          backbuffer_needs_clear_bits_ |= GL_COLOR_BUFFER_BIT;
          break;
        case GL_DEPTH_EXT:
          backbuffer_needs_clear_bits_ |= GL_DEPTH_BUFFER_BIT;
        case GL_STENCIL_EXT:
          backbuffer_needs_clear_bits_ |= GL_STENCIL_BUFFER_BIT;
          break;
        default:
          NOTREACHED();
          break;
      }
    }
  }

  // If the default framebuffer is bound but we are still rendering to an
  // FBO, translate attachment names that refer to default framebuffer
  // channels to corresponding framebuffer attachments.
  scoped_ptr<GLenum[]> translated_attachments(new GLenum[numAttachments]);
  for (GLsizei i = 0; i < numAttachments; ++i) {
    GLenum attachment = attachments[i];
    if (!framebuffer && GetBackbufferServiceId()) {
      switch (attachment) {
        case GL_COLOR_EXT:
          attachment = GL_COLOR_ATTACHMENT0;
          break;
        case GL_DEPTH_EXT:
          attachment = GL_DEPTH_ATTACHMENT;
          break;
        case GL_STENCIL_EXT:
          attachment = GL_STENCIL_ATTACHMENT;
          break;
        default:
          NOTREACHED();
          return;
      }
    }
    translated_attachments[i] = attachment;
  }

  glDiscardFramebufferEXT(target, numAttachments, translated_attachments.get());
}

void GLES2DecoderImpl::DoEnableVertexAttribArray(GLuint index) {
  if (state_.vertex_attrib_manager->Enable(index, true)) {
    glEnableVertexAttribArray(index);
  } else {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_VALUE, "glEnableVertexAttribArray", "index out of range");
  }
}

void GLES2DecoderImpl::DoGenerateMipmap(GLenum target) {
  TextureRef* texture_ref = texture_manager()->GetTextureInfoForTarget(
      &state_, target);
  if (!texture_ref ||
      !texture_manager()->CanGenerateMipmaps(texture_ref)) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_OPERATION, "glGenerateMipmap", "Can not generate mips");
    return;
  }

  if (target == GL_TEXTURE_CUBE_MAP) {
    for (int i = 0; i < 6; ++i) {
      GLenum face = GL_TEXTURE_CUBE_MAP_POSITIVE_X + i;
      if (!texture_manager()->ClearTextureLevel(this, texture_ref, face, 0)) {
        LOCAL_SET_GL_ERROR(
            GL_OUT_OF_MEMORY, "glGenerateMipmap", "dimensions too big");
        return;
      }
    }
  } else {
    if (!texture_manager()->ClearTextureLevel(this, texture_ref, target, 0)) {
      LOCAL_SET_GL_ERROR(
          GL_OUT_OF_MEMORY, "glGenerateMipmap", "dimensions too big");
      return;
    }
  }

  LOCAL_COPY_REAL_GL_ERRORS_TO_WRAPPER("glGenerateMipmap");
  // Workaround for Mac driver bug. In the large scheme of things setting
  // glTexParamter twice for glGenerateMipmap is probably not a lage performance
  // hit so there's probably no need to make this conditional. The bug appears
  // to be that if the filtering mode is set to something that doesn't require
  // mipmaps for rendering, or is never set to something other than the default,
  // then glGenerateMipmap misbehaves.
  if (workarounds().set_texture_filter_before_generating_mipmap) {
    glTexParameteri(target, GL_TEXTURE_MIN_FILTER, GL_NEAREST_MIPMAP_NEAREST);
  }
  glGenerateMipmapEXT(target);
  if (workarounds().set_texture_filter_before_generating_mipmap) {
    glTexParameteri(target, GL_TEXTURE_MIN_FILTER,
                    texture_ref->texture()->min_filter());
  }
  GLenum error = LOCAL_PEEK_GL_ERROR("glGenerateMipmap");
  if (error == GL_NO_ERROR) {
    texture_manager()->MarkMipmapsGenerated(texture_ref);
  }
}

bool GLES2DecoderImpl::GetHelper(
    GLenum pname, GLint* params, GLsizei* num_written) {
  DCHECK(num_written);
  if (gfx::GetGLImplementation() != gfx::kGLImplementationEGLGLES2) {
    switch (pname) {
      case GL_IMPLEMENTATION_COLOR_READ_FORMAT:
        *num_written = 1;
        // Return the GL implementation's preferred format and (see below type)
        // if we have the GL extension that exposes this. This allows the GPU
        // client to use the implementation's preferred format for glReadPixels
        // for optimisation.
        //
        // A conflicting extension (GL_ARB_ES2_compatibility) specifies an error
        // case when requested on integer/floating point buffers but which is
        // acceptable on GLES2 and with the GL_OES_read_format extension.
        //
        // Therefore if an error occurs we swallow the error and use the
        // internal implementation.
        if (params) {
          if (context_->HasExtension("GL_OES_read_format")) {
            ScopedGLErrorSuppressor suppressor("GLES2DecoderImpl::GetHelper",
                                               GetErrorState());
            glGetIntegerv(pname, params);
            if (glGetError() == GL_NO_ERROR)
              return true;
          }
          *params = GLES2Util::GetPreferredGLReadPixelsFormat(
              GetBoundReadFrameBufferInternalFormat());
        }
        return true;
      case GL_IMPLEMENTATION_COLOR_READ_TYPE:
        *num_written = 1;
        if (params) {
          if (context_->HasExtension("GL_OES_read_format")) {
            ScopedGLErrorSuppressor suppressor("GLES2DecoderImpl::GetHelper",
                                               GetErrorState());
            glGetIntegerv(pname, params);
            if (glGetError() == GL_NO_ERROR)
              return true;
          }
          *params = GLES2Util::GetPreferredGLReadPixelsType(
              GetBoundReadFrameBufferInternalFormat(),
              GetBoundReadFrameBufferTextureType());
        }
        return true;
      case GL_MAX_FRAGMENT_UNIFORM_VECTORS:
        *num_written = 1;
        if (params) {
          *params = group_->max_fragment_uniform_vectors();
        }
        return true;
      case GL_MAX_VARYING_VECTORS:
        *num_written = 1;
        if (params) {
          *params = group_->max_varying_vectors();
        }
        return true;
      case GL_MAX_VERTEX_UNIFORM_VECTORS:
        *num_written = 1;
        if (params) {
          *params = group_->max_vertex_uniform_vectors();
        }
        return true;
      }
  }
  switch (pname) {
    case GL_MAX_VIEWPORT_DIMS:
      if (offscreen_target_frame_buffer_.get()) {
        *num_written = 2;
        if (params) {
          params[0] = renderbuffer_manager()->max_renderbuffer_size();
          params[1] = renderbuffer_manager()->max_renderbuffer_size();
        }
        return true;
      }
      return false;
    case GL_MAX_SAMPLES:
      *num_written = 1;
      if (params) {
        params[0] = renderbuffer_manager()->max_samples();
      }
      return true;
    case GL_MAX_RENDERBUFFER_SIZE:
      *num_written = 1;
      if (params) {
        params[0] = renderbuffer_manager()->max_renderbuffer_size();
      }
      return true;
    case GL_MAX_TEXTURE_SIZE:
      *num_written = 1;
      if (params) {
        params[0] = texture_manager()->MaxSizeForTarget(GL_TEXTURE_2D);
      }
      return true;
    case GL_MAX_CUBE_MAP_TEXTURE_SIZE:
      *num_written = 1;
      if (params) {
        params[0] = texture_manager()->MaxSizeForTarget(GL_TEXTURE_CUBE_MAP);
      }
      return true;
    case GL_MAX_COLOR_ATTACHMENTS_EXT:
      *num_written = 1;
      if (params) {
        params[0] = group_->max_color_attachments();
      }
      return true;
    case GL_MAX_DRAW_BUFFERS_ARB:
      *num_written = 1;
      if (params) {
        params[0] = group_->max_draw_buffers();
      }
      return true;
    case GL_ALPHA_BITS:
      *num_written = 1;
      if (params) {
        GLint v = 0;
        glGetIntegerv(GL_ALPHA_BITS, &v);
        params[0] = BoundFramebufferHasColorAttachmentWithAlpha(false) ? v : 0;
      }
      return true;
    case GL_DEPTH_BITS:
      *num_written = 1;
      if (params) {
        GLint v = 0;
        glGetIntegerv(GL_DEPTH_BITS, &v);
        params[0] = BoundFramebufferHasDepthAttachment() ? v : 0;
      }
      return true;
    case GL_STENCIL_BITS:
      *num_written = 1;
      if (params) {
        GLint v = 0;
        glGetIntegerv(GL_STENCIL_BITS, &v);
        params[0] = BoundFramebufferHasStencilAttachment() ? v : 0;
      }
      return true;
    case GL_COMPRESSED_TEXTURE_FORMATS:
      *num_written = validators_->compressed_texture_format.GetValues().size();
      if (params) {
        for (GLint ii = 0; ii < *num_written; ++ii) {
          params[ii] = validators_->compressed_texture_format.GetValues()[ii];
        }
      }
      return true;
    case GL_NUM_COMPRESSED_TEXTURE_FORMATS:
      *num_written = 1;
      if (params) {
        *params = validators_->compressed_texture_format.GetValues().size();
      }
      return true;
    case GL_NUM_SHADER_BINARY_FORMATS:
      *num_written = 1;
      if (params) {
        *params = validators_->shader_binary_format.GetValues().size();
      }
      return true;
    case GL_SHADER_BINARY_FORMATS:
      *num_written = validators_->shader_binary_format.GetValues().size();
      if (params) {
        for (GLint ii = 0; ii <  *num_written; ++ii) {
          params[ii] = validators_->shader_binary_format.GetValues()[ii];
        }
      }
      return true;
    case GL_SHADER_COMPILER:
      *num_written = 1;
      if (params) {
        *params = GL_TRUE;
      }
      return true;
    case GL_ARRAY_BUFFER_BINDING:
      *num_written = 1;
      if (params) {
        if (state_.bound_array_buffer.get()) {
          GLuint client_id = 0;
          buffer_manager()->GetClientId(state_.bound_array_buffer->service_id(),
                                        &client_id);
          *params = client_id;
        } else {
          *params = 0;
        }
      }
      return true;
    case GL_ELEMENT_ARRAY_BUFFER_BINDING:
      *num_written = 1;
      if (params) {
        if (state_.vertex_attrib_manager->element_array_buffer()) {
          GLuint client_id = 0;
          buffer_manager()->GetClientId(
              state_.vertex_attrib_manager->element_array_buffer()->
                  service_id(), &client_id);
          *params = client_id;
        } else {
          *params = 0;
        }
      }
      return true;
    case GL_FRAMEBUFFER_BINDING:
    // case GL_DRAW_FRAMEBUFFER_BINDING_EXT: (same as GL_FRAMEBUFFER_BINDING)
      *num_written = 1;
      if (params) {
        Framebuffer* framebuffer =
            GetFramebufferInfoForTarget(GL_FRAMEBUFFER);
        if (framebuffer) {
          GLuint client_id = 0;
          framebuffer_manager()->GetClientId(
              framebuffer->service_id(), &client_id);
          *params = client_id;
        } else {
          *params = 0;
        }
      }
      return true;
    case GL_READ_FRAMEBUFFER_BINDING_EXT:
      *num_written = 1;
      if (params) {
        Framebuffer* framebuffer =
            GetFramebufferInfoForTarget(GL_READ_FRAMEBUFFER_EXT);
        if (framebuffer) {
          GLuint client_id = 0;
          framebuffer_manager()->GetClientId(
              framebuffer->service_id(), &client_id);
          *params = client_id;
        } else {
          *params = 0;
        }
      }
      return true;
    case GL_RENDERBUFFER_BINDING:
      *num_written = 1;
      if (params) {
        Renderbuffer* renderbuffer =
            GetRenderbufferInfoForTarget(GL_RENDERBUFFER);
        if (renderbuffer) {
          *params = renderbuffer->client_id();
        } else {
          *params = 0;
        }
      }
      return true;
    case GL_CURRENT_PROGRAM:
      *num_written = 1;
      if (params) {
        if (state_.current_program.get()) {
          GLuint client_id = 0;
          program_manager()->GetClientId(
              state_.current_program->service_id(), &client_id);
          *params = client_id;
        } else {
          *params = 0;
        }
      }
      return true;
    case GL_VERTEX_ARRAY_BINDING_OES:
      *num_written = 1;
      if (params) {
        if (state_.vertex_attrib_manager.get() !=
            default_vertex_attrib_manager_.get()) {
          GLuint client_id = 0;
          vertex_array_manager_->GetClientId(
              state_.vertex_attrib_manager->service_id(), &client_id);
          *params = client_id;
        } else {
          *params = 0;
        }
      }
      return true;
    case GL_TEXTURE_BINDING_2D:
      *num_written = 1;
      if (params) {
        TextureUnit& unit = state_.texture_units[state_.active_texture_unit];
        if (unit.bound_texture_2d.get()) {
          *params = unit.bound_texture_2d->client_id();
        } else {
          *params = 0;
        }
      }
      return true;
    case GL_TEXTURE_BINDING_CUBE_MAP:
      *num_written = 1;
      if (params) {
        TextureUnit& unit = state_.texture_units[state_.active_texture_unit];
        if (unit.bound_texture_cube_map.get()) {
          *params = unit.bound_texture_cube_map->client_id();
        } else {
          *params = 0;
        }
      }
      return true;
    case GL_TEXTURE_BINDING_EXTERNAL_OES:
      *num_written = 1;
      if (params) {
        TextureUnit& unit = state_.texture_units[state_.active_texture_unit];
        if (unit.bound_texture_external_oes.get()) {
          *params = unit.bound_texture_external_oes->client_id();
        } else {
          *params = 0;
        }
      }
      return true;
    case GL_TEXTURE_BINDING_RECTANGLE_ARB:
      *num_written = 1;
      if (params) {
        TextureUnit& unit = state_.texture_units[state_.active_texture_unit];
        if (unit.bound_texture_rectangle_arb.get()) {
          *params = unit.bound_texture_rectangle_arb->client_id();
        } else {
          *params = 0;
        }
      }
      return true;
    case GL_UNPACK_FLIP_Y_CHROMIUM:
      *num_written = 1;
      if (params) {
        params[0] = unpack_flip_y_;
      }
      return true;
    case GL_UNPACK_PREMULTIPLY_ALPHA_CHROMIUM:
      *num_written = 1;
      if (params) {
        params[0] = unpack_premultiply_alpha_;
      }
      return true;
    case GL_UNPACK_UNPREMULTIPLY_ALPHA_CHROMIUM:
      *num_written = 1;
      if (params) {
        params[0] = unpack_unpremultiply_alpha_;
      }
      return true;
    case GL_BIND_GENERATES_RESOURCE_CHROMIUM:
      *num_written = 1;
      if (params) {
        params[0] = group_->bind_generates_resource() ? 1 : 0;
      }
      return true;
    default:
      if (pname >= GL_DRAW_BUFFER0_ARB &&
          pname < GL_DRAW_BUFFER0_ARB + group_->max_draw_buffers()) {
        *num_written = 1;
        if (params) {
          Framebuffer* framebuffer =
              GetFramebufferInfoForTarget(GL_FRAMEBUFFER);
          if (framebuffer) {
            params[0] = framebuffer->GetDrawBuffer(pname);
          } else {  // backbuffer
            if (pname == GL_DRAW_BUFFER0_ARB)
              params[0] = group_->draw_buffer();
            else
              params[0] = GL_NONE;
          }
        }
        return true;
      }
      *num_written = util_.GLGetNumValuesReturned(pname);
      return false;
  }
}

bool GLES2DecoderImpl::GetNumValuesReturnedForGLGet(
    GLenum pname, GLsizei* num_values) {
  if (state_.GetStateAsGLint(pname, NULL, num_values)) {
    return true;
  }
  return GetHelper(pname, NULL, num_values);
}

GLenum GLES2DecoderImpl::AdjustGetPname(GLenum pname) {
  if (GL_MAX_SAMPLES == pname &&
      features().use_img_for_multisampled_render_to_texture) {
    return GL_MAX_SAMPLES_IMG;
  }
  return pname;
}

void GLES2DecoderImpl::DoGetBooleanv(GLenum pname, GLboolean* params) {
  DCHECK(params);
  GLsizei num_written = 0;
  if (GetNumValuesReturnedForGLGet(pname, &num_written)) {
    scoped_ptr<GLint[]> values(new GLint[num_written]);
    if (!state_.GetStateAsGLint(pname, values.get(), &num_written)) {
      GetHelper(pname, values.get(), &num_written);
    }
    for (GLsizei ii = 0; ii < num_written; ++ii) {
      params[ii] = static_cast<GLboolean>(values[ii]);
    }
  } else {
    pname = AdjustGetPname(pname);
    glGetBooleanv(pname, params);
  }
}

void GLES2DecoderImpl::DoGetFloatv(GLenum pname, GLfloat* params) {
  DCHECK(params);
  GLsizei num_written = 0;
  if (!state_.GetStateAsGLfloat(pname, params, &num_written)) {
    if (GetHelper(pname, NULL, &num_written)) {
      scoped_ptr<GLint[]> values(new GLint[num_written]);
      GetHelper(pname, values.get(), &num_written);
      for (GLsizei ii = 0; ii < num_written; ++ii) {
        params[ii] = static_cast<GLfloat>(values[ii]);
      }
    } else {
      pname = AdjustGetPname(pname);
      glGetFloatv(pname, params);
    }
  }
}

void GLES2DecoderImpl::DoGetIntegerv(GLenum pname, GLint* params) {
  DCHECK(params);
  GLsizei num_written;
  if (!state_.GetStateAsGLint(pname, params, &num_written) &&
      !GetHelper(pname, params, &num_written)) {
    pname = AdjustGetPname(pname);
    glGetIntegerv(pname, params);
  }
}

void GLES2DecoderImpl::DoGetProgramiv(
    GLuint program_id, GLenum pname, GLint* params) {
  Program* program = GetProgramInfoNotShader(program_id, "glGetProgramiv");
  if (!program) {
    return;
  }
  program->GetProgramiv(pname, params);
}

void GLES2DecoderImpl::DoGetBufferParameteriv(
    GLenum target, GLenum pname, GLint* params) {
  // Just delegate it. Some validation is actually done before this.
  buffer_manager()->ValidateAndDoGetBufferParameteriv(
      &state_, target, pname, params);
}

void GLES2DecoderImpl::DoBindAttribLocation(
    GLuint program_id, GLuint index, const char* name) {
  if (!StringIsValidForGLES(name)) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_VALUE, "glBindAttribLocation", "Invalid character");
    return;
  }
  if (ProgramManager::IsInvalidPrefix(name, strlen(name))) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_OPERATION, "glBindAttribLocation", "reserved prefix");
    return;
  }
  if (index >= group_->max_vertex_attribs()) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_VALUE, "glBindAttribLocation", "index out of range");
    return;
  }
  Program* program = GetProgramInfoNotShader(
      program_id, "glBindAttribLocation");
  if (!program) {
    return;
  }
  program->SetAttribLocationBinding(name, static_cast<GLint>(index));
  glBindAttribLocation(program->service_id(), index, name);
}

error::Error GLES2DecoderImpl::HandleBindAttribLocation(
    uint32 immediate_data_size, const cmds::BindAttribLocation& c) {
  GLuint program = static_cast<GLuint>(c.program);
  GLuint index = static_cast<GLuint>(c.index);
  uint32 name_size = c.data_size;
  const char* name = GetSharedMemoryAs<const char*>(
      c.name_shm_id, c.name_shm_offset, name_size);
  if (name == NULL) {
    return error::kOutOfBounds;
  }
  String name_str(name, name_size);
  DoBindAttribLocation(program, index, name_str.c_str());
  return error::kNoError;
}

error::Error GLES2DecoderImpl::HandleBindAttribLocationBucket(
    uint32 immediate_data_size, const cmds::BindAttribLocationBucket& c) {
  GLuint program = static_cast<GLuint>(c.program);
  GLuint index = static_cast<GLuint>(c.index);
  Bucket* bucket = GetBucket(c.name_bucket_id);
  if (!bucket || bucket->size() == 0) {
    return error::kInvalidArguments;
  }
  std::string name_str;
  if (!bucket->GetAsString(&name_str)) {
    return error::kInvalidArguments;
  }
  DoBindAttribLocation(program, index, name_str.c_str());
  return error::kNoError;
}

void GLES2DecoderImpl::DoBindUniformLocationCHROMIUM(
    GLuint program_id, GLint location, const char* name) {
  if (!StringIsValidForGLES(name)) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_VALUE,
        "glBindUniformLocationCHROMIUM", "Invalid character");
    return;
  }
  if (ProgramManager::IsInvalidPrefix(name, strlen(name))) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_OPERATION,
        "glBindUniformLocationCHROMIUM", "reserved prefix");
    return;
  }
  if (location < 0 || static_cast<uint32>(location) >=
      (group_->max_fragment_uniform_vectors() +
       group_->max_vertex_uniform_vectors()) * 4) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_VALUE,
        "glBindUniformLocationCHROMIUM", "location out of range");
    return;
  }
  Program* program = GetProgramInfoNotShader(
      program_id, "glBindUniformLocationCHROMIUM");
  if (!program) {
    return;
  }
  if (!program->SetUniformLocationBinding(name, location)) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_VALUE,
        "glBindUniformLocationCHROMIUM", "location out of range");
  }
}

error::Error GLES2DecoderImpl::HandleBindUniformLocationCHROMIUM(
    uint32 immediate_data_size, const cmds::BindUniformLocationCHROMIUM& c) {
  GLuint program = static_cast<GLuint>(c.program);
  GLint location = static_cast<GLint>(c.location);
  uint32 name_size = c.data_size;
  const char* name = GetSharedMemoryAs<const char*>(
      c.name_shm_id, c.name_shm_offset, name_size);
  if (name == NULL) {
    return error::kOutOfBounds;
  }
  String name_str(name, name_size);
  DoBindUniformLocationCHROMIUM(program, location, name_str.c_str());
  return error::kNoError;
}

error::Error GLES2DecoderImpl::HandleBindUniformLocationCHROMIUMBucket(
    uint32 immediate_data_size,
    const cmds::BindUniformLocationCHROMIUMBucket& c) {
  GLuint program = static_cast<GLuint>(c.program);
  GLint location = static_cast<GLint>(c.location);
  Bucket* bucket = GetBucket(c.name_bucket_id);
  if (!bucket || bucket->size() == 0) {
    return error::kInvalidArguments;
  }
  std::string name_str;
  if (!bucket->GetAsString(&name_str)) {
    return error::kInvalidArguments;
  }
  DoBindUniformLocationCHROMIUM(program, location, name_str.c_str());
  return error::kNoError;
}

error::Error GLES2DecoderImpl::HandleDeleteShader(
    uint32 immediate_data_size, const cmds::DeleteShader& c) {
  GLuint client_id = c.shader;
  if (client_id) {
    Shader* shader = GetShader(client_id);
    if (shader) {
      if (!shader->IsDeleted()) {
        glDeleteShader(shader->service_id());
        shader_manager()->MarkAsDeleted(shader);
      }
    } else {
      LOCAL_SET_GL_ERROR(GL_INVALID_VALUE, "glDeleteShader", "unknown shader");
    }
  }
  return error::kNoError;
}

error::Error GLES2DecoderImpl::HandleDeleteProgram(
    uint32 immediate_data_size, const cmds::DeleteProgram& c) {
  GLuint client_id = c.program;
  if (client_id) {
    Program* program = GetProgram(client_id);
    if (program) {
      if (!program->IsDeleted()) {
        program_manager()->MarkAsDeleted(shader_manager(), program);
      }
    } else {
      LOCAL_SET_GL_ERROR(
          GL_INVALID_VALUE, "glDeleteProgram", "unknown program");
    }
  }
  return error::kNoError;
}

void GLES2DecoderImpl::DoDeleteSharedIdsCHROMIUM(
    GLuint namespace_id, GLsizei n, const GLuint* ids) {
  IdAllocatorInterface* id_allocator = group_->GetIdAllocator(namespace_id);
  for (GLsizei ii = 0; ii < n; ++ii) {
    id_allocator->FreeID(ids[ii]);
  }
}

error::Error GLES2DecoderImpl::HandleDeleteSharedIdsCHROMIUM(
    uint32 immediate_data_size, const cmds::DeleteSharedIdsCHROMIUM& c) {
  GLuint namespace_id = static_cast<GLuint>(c.namespace_id);
  GLsizei n = static_cast<GLsizei>(c.n);
  uint32 data_size;
  if (!SafeMultiplyUint32(n, sizeof(GLuint), &data_size)) {
    return error::kOutOfBounds;
  }
  const GLuint* ids = GetSharedMemoryAs<const GLuint*>(
      c.ids_shm_id, c.ids_shm_offset, data_size);
  if (n < 0) {
    LOCAL_SET_GL_ERROR(GL_INVALID_VALUE, "DeleteSharedIdsCHROMIUM", "n < 0");
    return error::kNoError;
  }
  if (ids == NULL) {
    return error::kOutOfBounds;
  }
  DoDeleteSharedIdsCHROMIUM(namespace_id, n, ids);
  return error::kNoError;
}

void GLES2DecoderImpl::DoGenSharedIdsCHROMIUM(
    GLuint namespace_id, GLuint id_offset, GLsizei n, GLuint* ids) {
  IdAllocatorInterface* id_allocator = group_->GetIdAllocator(namespace_id);
  if (id_offset == 0) {
    for (GLsizei ii = 0; ii < n; ++ii) {
      ids[ii] = id_allocator->AllocateID();
    }
  } else {
    for (GLsizei ii = 0; ii < n; ++ii) {
      ids[ii] = id_allocator->AllocateIDAtOrAbove(id_offset);
      id_offset = ids[ii] + 1;
    }
  }
}

error::Error GLES2DecoderImpl::HandleGenSharedIdsCHROMIUM(
    uint32 immediate_data_size, const cmds::GenSharedIdsCHROMIUM& c) {
  GLuint namespace_id = static_cast<GLuint>(c.namespace_id);
  GLuint id_offset = static_cast<GLuint>(c.id_offset);
  GLsizei n = static_cast<GLsizei>(c.n);
  uint32 data_size;
  if (!SafeMultiplyUint32(n, sizeof(GLuint), &data_size)) {
    return error::kOutOfBounds;
  }
  GLuint* ids = GetSharedMemoryAs<GLuint*>(
      c.ids_shm_id, c.ids_shm_offset, data_size);
  if (n < 0) {
    LOCAL_SET_GL_ERROR(GL_INVALID_VALUE, "GenSharedIdsCHROMIUM", "n < 0");
    return error::kNoError;
  }
  if (ids == NULL) {
    return error::kOutOfBounds;
  }
  DoGenSharedIdsCHROMIUM(namespace_id, id_offset, n, ids);
  return error::kNoError;
}

void GLES2DecoderImpl::DoRegisterSharedIdsCHROMIUM(
    GLuint namespace_id, GLsizei n, const GLuint* ids) {
  IdAllocatorInterface* id_allocator = group_->GetIdAllocator(namespace_id);
  for (GLsizei ii = 0; ii < n; ++ii) {
    if (!id_allocator->MarkAsUsed(ids[ii])) {
      for (GLsizei jj = 0; jj < ii; ++jj) {
        id_allocator->FreeID(ids[jj]);
      }
      LOCAL_SET_GL_ERROR(
          GL_INVALID_VALUE, "RegisterSharedIdsCHROMIUM",
          "attempt to register id that already exists");
      return;
    }
  }
}

error::Error GLES2DecoderImpl::HandleRegisterSharedIdsCHROMIUM(
    uint32 immediate_data_size, const cmds::RegisterSharedIdsCHROMIUM& c) {
  GLuint namespace_id = static_cast<GLuint>(c.namespace_id);
  GLsizei n = static_cast<GLsizei>(c.n);
  uint32 data_size;
  if (!SafeMultiplyUint32(n, sizeof(GLuint), &data_size)) {
    return error::kOutOfBounds;
  }
  GLuint* ids = GetSharedMemoryAs<GLuint*>(
      c.ids_shm_id, c.ids_shm_offset, data_size);
  if (n < 0) {
    LOCAL_SET_GL_ERROR(GL_INVALID_VALUE, "RegisterSharedIdsCHROMIUM", "n < 0");
    return error::kNoError;
  }
  if (ids == NULL) {
    return error::kOutOfBounds;
  }
  DoRegisterSharedIdsCHROMIUM(namespace_id, n, ids);
  return error::kNoError;
}

error::Error GLES2DecoderImpl::DoClear(GLbitfield mask) {
  DCHECK(!ShouldDeferDraws());
  if (CheckBoundFramebuffersValid("glClear")) {
    ApplyDirtyState();
    glClear(mask);
  }
  return error::kNoError;
}

void GLES2DecoderImpl::DoFramebufferRenderbuffer(
    GLenum target, GLenum attachment, GLenum renderbuffertarget,
    GLuint client_renderbuffer_id) {
  Framebuffer* framebuffer = GetFramebufferInfoForTarget(target);
  if (!framebuffer) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_OPERATION,
        "glFramebufferRenderbuffer", "no framebuffer bound");
    return;
  }
  GLuint service_id = 0;
  Renderbuffer* renderbuffer = NULL;
  if (client_renderbuffer_id) {
    renderbuffer = GetRenderbuffer(client_renderbuffer_id);
    if (!renderbuffer) {
      LOCAL_SET_GL_ERROR(
          GL_INVALID_OPERATION,
          "glFramebufferRenderbuffer", "unknown renderbuffer");
      return;
    }
    service_id = renderbuffer->service_id();
  }
  LOCAL_COPY_REAL_GL_ERRORS_TO_WRAPPER("glFramebufferRenderbuffer");
  glFramebufferRenderbufferEXT(
      target, attachment, renderbuffertarget, service_id);
  GLenum error = LOCAL_PEEK_GL_ERROR("glFramebufferRenderbuffer");
  if (error == GL_NO_ERROR) {
    framebuffer->AttachRenderbuffer(attachment, renderbuffer);
  }
  if (framebuffer == framebuffer_state_.bound_draw_framebuffer.get()) {
    framebuffer_state_.clear_state_dirty = true;
  }
  OnFboChanged();
}

void GLES2DecoderImpl::DoDisable(GLenum cap) {
  if (SetCapabilityState(cap, false)) {
    glDisable(cap);
  }
}

void GLES2DecoderImpl::DoEnable(GLenum cap) {
  if (SetCapabilityState(cap, true)) {
    glEnable(cap);
  }
}

void GLES2DecoderImpl::DoDepthRangef(GLclampf znear, GLclampf zfar) {
  state_.z_near = std::min(1.0f, std::max(0.0f, znear));
  state_.z_far = std::min(1.0f, std::max(0.0f, zfar));
  glDepthRange(znear, zfar);
}

void GLES2DecoderImpl::DoSampleCoverage(GLclampf value, GLboolean invert) {
  state_.sample_coverage_value = std::min(1.0f, std::max(0.0f, value));
  state_.sample_coverage_invert = (invert != 0);
  glSampleCoverage(state_.sample_coverage_value, invert);
}

// Assumes framebuffer is complete.
void GLES2DecoderImpl::ClearUnclearedAttachments(
    GLenum target, Framebuffer* framebuffer) {
  if (target == GL_READ_FRAMEBUFFER_EXT) {
    // bind this to the DRAW point, clear then bind back to READ
    // TODO(gman): I don't think there is any guarantee that an FBO that
    //   is complete on the READ attachment will be complete as a DRAW
    //   attachment.
    glBindFramebufferEXT(GL_READ_FRAMEBUFFER_EXT, 0);
    glBindFramebufferEXT(GL_DRAW_FRAMEBUFFER_EXT, framebuffer->service_id());
  }
  GLbitfield clear_bits = 0;
  if (framebuffer->HasUnclearedAttachment(GL_COLOR_ATTACHMENT0)) {
    glClearColor(
        0.0f, 0.0f, 0.0f,
        (GLES2Util::GetChannelsForFormat(
             framebuffer->GetColorAttachmentFormat()) & 0x0008) != 0 ? 0.0f :
                                                                       1.0f);
    glColorMask(true, true, true, true);
    clear_bits |= GL_COLOR_BUFFER_BIT;
  }

  if (framebuffer->HasUnclearedAttachment(GL_STENCIL_ATTACHMENT) ||
      framebuffer->HasUnclearedAttachment(GL_DEPTH_STENCIL_ATTACHMENT)) {
    glClearStencil(0);
    glStencilMask(-1);
    clear_bits |= GL_STENCIL_BUFFER_BIT;
  }

  if (framebuffer->HasUnclearedAttachment(GL_DEPTH_ATTACHMENT) ||
      framebuffer->HasUnclearedAttachment(GL_DEPTH_STENCIL_ATTACHMENT)) {
    glClearDepth(1.0f);
    glDepthMask(true);
    clear_bits |= GL_DEPTH_BUFFER_BIT;
  }

  glDisable(GL_SCISSOR_TEST);
  glClear(clear_bits);

  framebuffer_manager()->MarkAttachmentsAsCleared(
      framebuffer, renderbuffer_manager(), texture_manager());

  RestoreClearState();

  if (target == GL_READ_FRAMEBUFFER_EXT) {
    glBindFramebufferEXT(GL_READ_FRAMEBUFFER_EXT, framebuffer->service_id());
    Framebuffer* draw_framebuffer =
        GetFramebufferInfoForTarget(GL_DRAW_FRAMEBUFFER_EXT);
    GLuint service_id = draw_framebuffer ? draw_framebuffer->service_id() :
                                           GetBackbufferServiceId();
    glBindFramebufferEXT(GL_DRAW_FRAMEBUFFER_EXT, service_id);
  }
}

void GLES2DecoderImpl::RestoreClearState() {
  framebuffer_state_.clear_state_dirty = true;
  glClearColor(
      state_.color_clear_red, state_.color_clear_green, state_.color_clear_blue,
      state_.color_clear_alpha);
  glClearStencil(state_.stencil_clear);
  glClearDepth(state_.depth_clear);
  if (state_.enable_flags.scissor_test) {
    glEnable(GL_SCISSOR_TEST);
  }
}

GLenum GLES2DecoderImpl::DoCheckFramebufferStatus(GLenum target) {
  Framebuffer* framebuffer =
      GetFramebufferInfoForTarget(target);
  if (!framebuffer) {
    return GL_FRAMEBUFFER_COMPLETE;
  }
  GLenum completeness = framebuffer->IsPossiblyComplete();
  if (completeness != GL_FRAMEBUFFER_COMPLETE) {
    return completeness;
  }
  return framebuffer->GetStatus(texture_manager(), target);
}

void GLES2DecoderImpl::DoFramebufferTexture2D(
    GLenum target, GLenum attachment, GLenum textarget,
    GLuint client_texture_id, GLint level) {
  DoFramebufferTexture2DCommon(
    "glFramebufferTexture2D", target, attachment,
    textarget, client_texture_id, level, 0);
}

void GLES2DecoderImpl::DoFramebufferTexture2DMultisample(
    GLenum target, GLenum attachment, GLenum textarget,
    GLuint client_texture_id, GLint level, GLsizei samples) {
  if (!features().multisampled_render_to_texture) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_OPERATION,
        "glFramebufferTexture2DMultisample", "function not available");
    return;
  }
  DoFramebufferTexture2DCommon(
    "glFramebufferTexture2DMultisample", target, attachment,
    textarget, client_texture_id, level, samples);
}

void GLES2DecoderImpl::DoFramebufferTexture2DCommon(
    const char* name, GLenum target, GLenum attachment, GLenum textarget,
    GLuint client_texture_id, GLint level, GLsizei samples) {
  if (samples > renderbuffer_manager()->max_samples()) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_VALUE,
        "glFramebufferTexture2DMultisample", "samples too large");
    return;
  }
  Framebuffer* framebuffer = GetFramebufferInfoForTarget(target);
  if (!framebuffer) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_OPERATION,
        name, "no framebuffer bound.");
    return;
  }
  GLuint service_id = 0;
  TextureRef* texture_ref = NULL;
  if (client_texture_id) {
    texture_ref = GetTexture(client_texture_id);
    if (!texture_ref) {
      LOCAL_SET_GL_ERROR(
          GL_INVALID_OPERATION,
          name, "unknown texture_ref");
      return;
    }
    service_id = texture_ref->service_id();
  }

  if (!texture_manager()->ValidForTarget(textarget, level, 0, 0, 1)) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_VALUE,
        name, "level out of range");
    return;
  }

  if (texture_ref)
    DoWillUseTexImageIfNeeded(texture_ref->texture(), textarget);

  LOCAL_COPY_REAL_GL_ERRORS_TO_WRAPPER(name);
  if (0 == samples) {
    glFramebufferTexture2DEXT(target, attachment, textarget, service_id, level);
  } else {
    if (features().use_img_for_multisampled_render_to_texture) {
      glFramebufferTexture2DMultisampleIMG(target, attachment, textarget,
          service_id, level, samples);
    } else {
      glFramebufferTexture2DMultisampleEXT(target, attachment, textarget,
          service_id, level, samples);
    }
  }
  GLenum error = LOCAL_PEEK_GL_ERROR(name);
  if (error == GL_NO_ERROR) {
    framebuffer->AttachTexture(attachment, texture_ref, textarget, level,
         samples);
  }
  if (framebuffer == framebuffer_state_.bound_draw_framebuffer.get()) {
    framebuffer_state_.clear_state_dirty = true;
  }

  if (texture_ref)
    DoDidUseTexImageIfNeeded(texture_ref->texture(), textarget);

  OnFboChanged();
}

void GLES2DecoderImpl::DoGetFramebufferAttachmentParameteriv(
    GLenum target, GLenum attachment, GLenum pname, GLint* params) {
  Framebuffer* framebuffer = GetFramebufferInfoForTarget(target);
  if (!framebuffer) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_OPERATION,
        "glGetFramebufferAttachmentParameteriv", "no framebuffer bound");
    return;
  }
  if (pname == GL_FRAMEBUFFER_ATTACHMENT_OBJECT_NAME) {
    const Framebuffer::Attachment* attachment_object =
        framebuffer->GetAttachment(attachment);
    *params = attachment_object ? attachment_object->object_name() : 0;
  } else {
    if (pname == GL_FRAMEBUFFER_ATTACHMENT_TEXTURE_SAMPLES_EXT &&
        features().use_img_for_multisampled_render_to_texture) {
      pname = GL_TEXTURE_SAMPLES_IMG;
    }
    glGetFramebufferAttachmentParameterivEXT(target, attachment, pname, params);
  }
}

void GLES2DecoderImpl::DoGetRenderbufferParameteriv(
    GLenum target, GLenum pname, GLint* params) {
  Renderbuffer* renderbuffer =
      GetRenderbufferInfoForTarget(GL_RENDERBUFFER);
  if (!renderbuffer) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_OPERATION,
        "glGetRenderbufferParameteriv", "no renderbuffer bound");
    return;
  }
  switch (pname) {
    case GL_RENDERBUFFER_INTERNAL_FORMAT:
      *params = renderbuffer->internal_format();
      break;
    case GL_RENDERBUFFER_WIDTH:
      *params = renderbuffer->width();
      break;
    case GL_RENDERBUFFER_HEIGHT:
      *params = renderbuffer->height();
      break;
    case GL_RENDERBUFFER_SAMPLES_EXT:
      if (features().use_img_for_multisampled_render_to_texture) {
        glGetRenderbufferParameterivEXT(target, GL_RENDERBUFFER_SAMPLES_IMG,
            params);
      } else {
        glGetRenderbufferParameterivEXT(target, GL_RENDERBUFFER_SAMPLES_EXT,
            params);
      }
    default:
      glGetRenderbufferParameterivEXT(target, pname, params);
      break;
  }
}

void GLES2DecoderImpl::DoBlitFramebufferCHROMIUM(
    GLint srcX0, GLint srcY0, GLint srcX1, GLint srcY1,
    GLint dstX0, GLint dstY0, GLint dstX1, GLint dstY1,
    GLbitfield mask, GLenum filter) {
  DCHECK(!ShouldDeferReads() && !ShouldDeferDraws());
  if (!features().chromium_framebuffer_multisample) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_OPERATION,
        "glBlitFramebufferCHROMIUM", "function not available");
    return;
  }

  if (!CheckBoundFramebuffersValid("glBlitFramebufferCHROMIUM")) {
    return;
  }

  glDisable(GL_SCISSOR_TEST);
  BlitFramebufferHelper(
      srcX0, srcY0, srcX1, srcY1, dstX0, dstY0, dstX1, dstY1, mask, filter);
  EnableDisable(GL_SCISSOR_TEST, state_.enable_flags.scissor_test);
}

void GLES2DecoderImpl::RenderbufferStorageMultisampleHelper(
    const FeatureInfo* feature_info,
    GLenum target,
    GLsizei samples,
    GLenum internal_format,
    GLsizei width,
    GLsizei height) {
  // TODO(sievers): This could be resolved at the GL binding level, but the
  // binding process is currently a bit too 'brute force'.
  if (feature_info->feature_flags().is_angle) {
    glRenderbufferStorageMultisampleANGLE(
        target, samples, internal_format, width, height);
  } else if (feature_info->feature_flags().use_core_framebuffer_multisample) {
    glRenderbufferStorageMultisample(
        target, samples, internal_format, width, height);
  } else {
    glRenderbufferStorageMultisampleEXT(
        target, samples, internal_format, width, height);
  }
}

void GLES2DecoderImpl::BlitFramebufferHelper(GLint srcX0,
                                             GLint srcY0,
                                             GLint srcX1,
                                             GLint srcY1,
                                             GLint dstX0,
                                             GLint dstY0,
                                             GLint dstX1,
                                             GLint dstY1,
                                             GLbitfield mask,
                                             GLenum filter) {
  // TODO(sievers): This could be resolved at the GL binding level, but the
  // binding process is currently a bit too 'brute force'.
  if (feature_info_->feature_flags().is_angle) {
    glBlitFramebufferANGLE(
        srcX0, srcY0, srcX1, srcY1, dstX0, dstY0, dstX1, dstY1, mask, filter);
  } else if (feature_info_->feature_flags().use_core_framebuffer_multisample) {
    glBlitFramebuffer(
        srcX0, srcY0, srcX1, srcY1, dstX0, dstY0, dstX1, dstY1, mask, filter);
  } else {
    glBlitFramebufferEXT(
        srcX0, srcY0, srcX1, srcY1, dstX0, dstY0, dstX1, dstY1, mask, filter);
  }
}

bool GLES2DecoderImpl::ValidateRenderbufferStorageMultisample(
    GLsizei samples,
    GLenum internalformat,
    GLsizei width,
    GLsizei height) {
  if (samples > renderbuffer_manager()->max_samples()) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_VALUE,
        "glRenderbufferStorageMultisample", "samples too large");
    return false;
  }

  if (width > renderbuffer_manager()->max_renderbuffer_size() ||
      height > renderbuffer_manager()->max_renderbuffer_size()) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_VALUE,
        "glRenderbufferStorageMultisample", "dimensions too large");
    return false;
  }

  uint32 estimated_size = 0;
  if (!renderbuffer_manager()->ComputeEstimatedRenderbufferSize(
           width, height, samples, internalformat, &estimated_size)) {
    LOCAL_SET_GL_ERROR(
        GL_OUT_OF_MEMORY,
        "glRenderbufferStorageMultisample", "dimensions too large");
    return false;
  }

  if (!EnsureGPUMemoryAvailable(estimated_size)) {
    LOCAL_SET_GL_ERROR(
        GL_OUT_OF_MEMORY,
        "glRenderbufferStorageMultisample", "out of memory");
    return false;
  }

  return true;
}

void GLES2DecoderImpl::DoRenderbufferStorageMultisampleCHROMIUM(
    GLenum target, GLsizei samples, GLenum internalformat,
    GLsizei width, GLsizei height) {
  if (!features().chromium_framebuffer_multisample) {
    LOCAL_SET_GL_ERROR(GL_INVALID_OPERATION,
                       "glRenderbufferStorageMultisampleCHROMIUM",
                       "function not available");
    return;
  }

  Renderbuffer* renderbuffer = GetRenderbufferInfoForTarget(GL_RENDERBUFFER);
  if (!renderbuffer) {
    LOCAL_SET_GL_ERROR(GL_INVALID_OPERATION,
                       "glRenderbufferStorageMultisampleCHROMIUM",
                       "no renderbuffer bound");
    return;
  }

  if (!ValidateRenderbufferStorageMultisample(
      samples, internalformat, width, height)) {
    return;
  }

  GLenum impl_format =
      renderbuffer_manager()->InternalRenderbufferFormatToImplFormat(
          internalformat);
  LOCAL_COPY_REAL_GL_ERRORS_TO_WRAPPER(
      "glRenderbufferStorageMultisampleCHROMIUM");
  RenderbufferStorageMultisampleHelper(
      feature_info_, target, samples, impl_format, width, height);
  GLenum error =
      LOCAL_PEEK_GL_ERROR("glRenderbufferStorageMultisampleCHROMIUM");
  if (error == GL_NO_ERROR) {

    if (workarounds().validate_multisample_buffer_allocation) {
      if (!VerifyMultisampleRenderbufferIntegrity(
          renderbuffer->service_id(), impl_format)) {
        LOCAL_SET_GL_ERROR(
            GL_OUT_OF_MEMORY,
            "glRenderbufferStorageMultisampleCHROMIUM", "out of memory");
        return;
      }
    }

    // TODO(gman): If renderbuffers tracked which framebuffers they were
    // attached to we could just mark those framebuffers as not complete.
    framebuffer_manager()->IncFramebufferStateChangeCount();
    renderbuffer_manager()->SetInfo(
        renderbuffer, samples, internalformat, width, height);
  }
}

// This is the handler for multisampled_render_to_texture extensions.
void GLES2DecoderImpl::DoRenderbufferStorageMultisampleEXT(
    GLenum target, GLsizei samples, GLenum internalformat,
    GLsizei width, GLsizei height) {
  if (!features().multisampled_render_to_texture) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_OPERATION,
        "glRenderbufferStorageMultisampleEXT", "function not available");
    return;
  }

  Renderbuffer* renderbuffer = GetRenderbufferInfoForTarget(GL_RENDERBUFFER);
  if (!renderbuffer) {
    LOCAL_SET_GL_ERROR(GL_INVALID_OPERATION,
                       "glRenderbufferStorageMultisampleEXT",
                       "no renderbuffer bound");
    return;
  }

  if (!ValidateRenderbufferStorageMultisample(
      samples, internalformat, width, height)) {
    return;
  }

  GLenum impl_format =
      renderbuffer_manager()->InternalRenderbufferFormatToImplFormat(
          internalformat);
  LOCAL_COPY_REAL_GL_ERRORS_TO_WRAPPER("glRenderbufferStorageMultisampleEXT");
  if (features().use_img_for_multisampled_render_to_texture) {
    glRenderbufferStorageMultisampleIMG(
        target, samples, impl_format, width, height);
  } else {
    glRenderbufferStorageMultisampleEXT(
        target, samples, impl_format, width, height);
  }
  GLenum error = LOCAL_PEEK_GL_ERROR("glRenderbufferStorageMultisampleEXT");
  if (error == GL_NO_ERROR) {
    // TODO(gman): If renderbuffers tracked which framebuffers they were
    // attached to we could just mark those framebuffers as not complete.
    framebuffer_manager()->IncFramebufferStateChangeCount();
    renderbuffer_manager()->SetInfo(
        renderbuffer, samples, internalformat, width, height);
  }
}

// This function validates the allocation of a multisampled renderbuffer
// by clearing it to a key color, blitting the contents to a texture, and
// reading back the color to ensure it matches the key.
bool GLES2DecoderImpl::VerifyMultisampleRenderbufferIntegrity(
    GLuint renderbuffer, GLenum format) {

  // Only validate color buffers.
  // These formats have been selected because they are very common or are known
  // to be used by the WebGL backbuffer. If problems are observed with other
  // color formats they can be added here.
  switch(format) {
    case GL_RGB:
    case GL_RGB8:
    case GL_RGBA:
    case GL_RGBA8:
      break;
    default:
      return true;
  }

  GLint draw_framebuffer, read_framebuffer;

  // Cache framebuffer and texture bindings.
  glGetIntegerv(GL_DRAW_FRAMEBUFFER_BINDING, &draw_framebuffer);
  glGetIntegerv(GL_READ_FRAMEBUFFER_BINDING, &read_framebuffer);

  if (!validation_texture_) {
    GLint bound_texture;
    glGetIntegerv(GL_TEXTURE_BINDING_2D, &bound_texture);

    // Create additional resources needed for the verification.
    glGenTextures(1, &validation_texture_);
    glGenFramebuffersEXT(1, &validation_fbo_multisample_);
    glGenFramebuffersEXT(1, &validation_fbo_);

    // Texture only needs to be 1x1.
    glBindTexture(GL_TEXTURE_2D, validation_texture_);
    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, 1, 1, 0, GL_RGB,
        GL_UNSIGNED_BYTE, NULL);

    glBindFramebufferEXT(GL_FRAMEBUFFER, validation_fbo_);
    glFramebufferTexture2DEXT(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
        GL_TEXTURE_2D, validation_texture_, 0);

    glBindTexture(GL_TEXTURE_2D, bound_texture);
  }

  glBindFramebufferEXT(GL_FRAMEBUFFER, validation_fbo_multisample_);
  glFramebufferRenderbufferEXT(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
      GL_RENDERBUFFER, renderbuffer);

  // Cache current state and reset it to the values we require.
  GLboolean scissor_enabled = false;
  glGetBooleanv(GL_SCISSOR_TEST, &scissor_enabled);
  if (scissor_enabled)
    glDisable(GL_SCISSOR_TEST);

  GLboolean color_mask[4] = {true, true, true, true};
  glGetBooleanv(GL_COLOR_WRITEMASK, color_mask);
  glColorMask(true, true, true, true);

  GLfloat clear_color[4] = {0.0f, 0.0f, 0.0f, 0.0f};
  glGetFloatv(GL_COLOR_CLEAR_VALUE, clear_color);
  glClearColor(1.0f, 0.0f, 1.0f, 1.0f);

  // Clear the buffer to the desired key color.
  glClear(GL_COLOR_BUFFER_BIT);

  // Blit from the multisample buffer to a standard texture.
  glBindFramebufferEXT(GL_READ_FRAMEBUFFER, validation_fbo_multisample_);
  glBindFramebufferEXT(GL_DRAW_FRAMEBUFFER, validation_fbo_);

  BlitFramebufferHelper(
      0, 0, 1, 1, 0, 0, 1, 1, GL_COLOR_BUFFER_BIT, GL_NEAREST);

  // Read a pixel from the buffer.
  glBindFramebufferEXT(GL_FRAMEBUFFER, validation_fbo_);

  unsigned char pixel[3] = {0, 0, 0};
  glReadPixels(0, 0, 1, 1, GL_RGB, GL_UNSIGNED_BYTE, &pixel);

  // Detach the renderbuffer.
  glBindFramebufferEXT(GL_FRAMEBUFFER, validation_fbo_multisample_);
  glFramebufferRenderbufferEXT(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
      GL_RENDERBUFFER, 0);

  // Restore cached state.
  if (scissor_enabled)
    glEnable(GL_SCISSOR_TEST);

  glColorMask(color_mask[0], color_mask[1], color_mask[2], color_mask[3]);
  glClearColor(clear_color[0], clear_color[1], clear_color[2], clear_color[3]);
  glBindFramebufferEXT(GL_DRAW_FRAMEBUFFER, draw_framebuffer);
  glBindFramebufferEXT(GL_READ_FRAMEBUFFER, read_framebuffer);

  // Return true if the pixel matched the desired key color.
  return (pixel[0] == 0xFF &&
      pixel[1] == 0x00 &&
      pixel[2] == 0xFF);
}

void GLES2DecoderImpl::DoRenderbufferStorage(
  GLenum target, GLenum internalformat, GLsizei width, GLsizei height) {
  Renderbuffer* renderbuffer =
      GetRenderbufferInfoForTarget(GL_RENDERBUFFER);
  if (!renderbuffer) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_OPERATION,
        "glRenderbufferStorage", "no renderbuffer bound");
    return;
  }

  if (width > renderbuffer_manager()->max_renderbuffer_size() ||
      height > renderbuffer_manager()->max_renderbuffer_size()) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_VALUE, "glRenderbufferStorage", "dimensions too large");
    return;
  }

  uint32 estimated_size = 0;
  if (!renderbuffer_manager()->ComputeEstimatedRenderbufferSize(
           width, height, 1, internalformat, &estimated_size)) {
    LOCAL_SET_GL_ERROR(
        GL_OUT_OF_MEMORY, "glRenderbufferStorage", "dimensions too large");
    return;
  }

  if (!EnsureGPUMemoryAvailable(estimated_size)) {
    LOCAL_SET_GL_ERROR(
        GL_OUT_OF_MEMORY, "glRenderbufferStorage", "out of memory");
    return;
  }

  LOCAL_COPY_REAL_GL_ERRORS_TO_WRAPPER("glRenderbufferStorage");
  glRenderbufferStorageEXT(
      target,
      renderbuffer_manager()->InternalRenderbufferFormatToImplFormat(
          internalformat),
      width,
      height);
  GLenum error = LOCAL_PEEK_GL_ERROR("glRenderbufferStorage");
  if (error == GL_NO_ERROR) {
    // TODO(gman): If tetxures tracked which framebuffers they were attached to
    // we could just mark those framebuffers as not complete.
    framebuffer_manager()->IncFramebufferStateChangeCount();
    renderbuffer_manager()->SetInfo(
        renderbuffer, 1, internalformat, width, height);
  }
}

void GLES2DecoderImpl::DoLinkProgram(GLuint program_id) {
  TRACE_EVENT0("gpu", "GLES2DecoderImpl::DoLinkProgram");
  Program* program = GetProgramInfoNotShader(
      program_id, "glLinkProgram");
  if (!program) {
    return;
  }

  LogClientServiceForInfo(program, program_id, "glLinkProgram");
  ShaderTranslator* vertex_translator = NULL;
  ShaderTranslator* fragment_translator = NULL;
  if (use_shader_translator_) {
    vertex_translator = vertex_translator_.get();
    fragment_translator = fragment_translator_.get();
  }
  if (program->Link(shader_manager(),
                    vertex_translator,
                    fragment_translator,
                    workarounds().count_all_in_varyings_packing ?
                        Program::kCountAll : Program::kCountOnlyStaticallyUsed,
                    shader_cache_callback_)) {
    if (program == state_.current_program.get()) {
      if (workarounds().use_current_program_after_successful_link)
        glUseProgram(program->service_id());
      if (workarounds().clear_uniforms_before_first_program_use)
        program_manager()->ClearUniforms(program);
    }
  }
};

void GLES2DecoderImpl::DoTexParameterf(
    GLenum target, GLenum pname, GLfloat param) {
  TextureRef* texture = texture_manager()->GetTextureInfoForTarget(
      &state_, target);
  if (!texture) {
    LOCAL_SET_GL_ERROR(GL_INVALID_VALUE, "glTexParameterf", "unknown texture");
    return;
  }

  texture_manager()->SetParameterf(
      "glTexParameterf", GetErrorState(), texture, pname, param);
}

void GLES2DecoderImpl::DoTexParameteri(
    GLenum target, GLenum pname, GLint param) {
  TextureRef* texture = texture_manager()->GetTextureInfoForTarget(
      &state_, target);
  if (!texture) {
    LOCAL_SET_GL_ERROR(GL_INVALID_VALUE, "glTexParameteri", "unknown texture");
    return;
  }

  texture_manager()->SetParameteri(
      "glTexParameteri", GetErrorState(), texture, pname, param);
}

void GLES2DecoderImpl::DoTexParameterfv(
    GLenum target, GLenum pname, const GLfloat* params) {
  TextureRef* texture = texture_manager()->GetTextureInfoForTarget(
      &state_, target);
  if (!texture) {
    LOCAL_SET_GL_ERROR(GL_INVALID_VALUE, "glTexParameterfv", "unknown texture");
    return;
  }

  texture_manager()->SetParameterf(
      "glTexParameterfv", GetErrorState(), texture, pname, *params);
}

void GLES2DecoderImpl::DoTexParameteriv(
  GLenum target, GLenum pname, const GLint* params) {
  TextureRef* texture = texture_manager()->GetTextureInfoForTarget(
      &state_, target);
  if (!texture) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_VALUE, "glTexParameteriv", "unknown texture");
    return;
  }

  texture_manager()->SetParameteri(
      "glTexParameteriv", GetErrorState(), texture, pname, *params);
}

bool GLES2DecoderImpl::CheckCurrentProgram(const char* function_name) {
  if (!state_.current_program.get()) {
    // The program does not exist.
    LOCAL_SET_GL_ERROR(
        GL_INVALID_OPERATION, function_name, "no program in use");
    return false;
  }
  if (!state_.current_program->InUse()) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_OPERATION, function_name, "program not linked");
    return false;
  }
  return true;
}

bool GLES2DecoderImpl::CheckCurrentProgramForUniform(
    GLint location, const char* function_name) {
  if (!CheckCurrentProgram(function_name)) {
    return false;
  }
  return location != -1;
}

bool GLES2DecoderImpl::PrepForSetUniformByLocation(
    GLint fake_location,
    const char* function_name,
    Program::UniformApiType api_type,
    GLint* real_location,
    GLenum* type,
    GLsizei* count) {
  DCHECK(type);
  DCHECK(count);
  DCHECK(real_location);

  if (!CheckCurrentProgramForUniform(fake_location, function_name)) {
    return false;
  }
  GLint array_index = -1;
  const Program::UniformInfo* info =
      state_.current_program->GetUniformInfoByFakeLocation(
          fake_location, real_location, &array_index);
  if (!info) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_OPERATION, function_name, "unknown location");
    return false;
  }

  if ((api_type & info->accepts_api_type) == 0) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_OPERATION, function_name,
        "wrong uniform function for type");
    return false;
  }
  if (*count > 1 && !info->is_array) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_OPERATION, function_name, "count > 1 for non-array");
    return false;
  }
  *count = std::min(info->size - array_index, *count);
  if (*count <= 0) {
    return false;
  }
  *type = info->type;
  return true;
}

void GLES2DecoderImpl::DoUniform1i(GLint fake_location, GLint v0) {
  GLenum type = 0;
  GLsizei count = 1;
  GLint real_location = -1;
  if (!PrepForSetUniformByLocation(fake_location,
                                   "glUniform1i",
                                   Program::kUniform1i,
                                   &real_location,
                                   &type,
                                   &count)) {
    return;
  }
  if (!state_.current_program->SetSamplers(
      state_.texture_units.size(), fake_location, 1, &v0)) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_VALUE, "glUniform1i", "texture unit out of range");
    return;
  }
  glUniform1i(real_location, v0);
}

void GLES2DecoderImpl::DoUniform1iv(
    GLint fake_location, GLsizei count, const GLint *value) {
  GLenum type = 0;
  GLint real_location = -1;
  if (!PrepForSetUniformByLocation(fake_location,
                                   "glUniform1iv",
                                   Program::kUniform1i,
                                   &real_location,
                                   &type,
                                   &count)) {
    return;
  }
  if (type == GL_SAMPLER_2D || type == GL_SAMPLER_2D_RECT_ARB ||
      type == GL_SAMPLER_CUBE || type == GL_SAMPLER_EXTERNAL_OES) {
    if (!state_.current_program->SetSamplers(
          state_.texture_units.size(), fake_location, count, value)) {
      LOCAL_SET_GL_ERROR(
          GL_INVALID_VALUE, "glUniform1iv", "texture unit out of range");
      return;
    }
  }
  glUniform1iv(real_location, count, value);
}

void GLES2DecoderImpl::DoUniform1fv(
    GLint fake_location, GLsizei count, const GLfloat* value) {
  GLenum type = 0;
  GLint real_location = -1;
  if (!PrepForSetUniformByLocation(fake_location,
                                   "glUniform1fv",
                                   Program::kUniform1f,
                                   &real_location,
                                   &type,
                                   &count)) {
    return;
  }
  if (type == GL_BOOL) {
    scoped_ptr<GLint[]> temp(new GLint[count]);
    for (GLsizei ii = 0; ii < count; ++ii) {
      temp[ii] = static_cast<GLint>(value[ii] != 0.0f);
    }
    DoUniform1iv(real_location, count, temp.get());
  } else {
    glUniform1fv(real_location, count, value);
  }
}

void GLES2DecoderImpl::DoUniform2fv(
    GLint fake_location, GLsizei count, const GLfloat* value) {
  GLenum type = 0;
  GLint real_location = -1;
  if (!PrepForSetUniformByLocation(fake_location,
                                   "glUniform2fv",
                                   Program::kUniform2f,
                                   &real_location,
                                   &type,
                                   &count)) {
    return;
  }
  if (type == GL_BOOL_VEC2) {
    GLsizei num_values = count * 2;
    scoped_ptr<GLint[]> temp(new GLint[num_values]);
    for (GLsizei ii = 0; ii < num_values; ++ii) {
      temp[ii] = static_cast<GLint>(value[ii] != 0.0f);
    }
    glUniform2iv(real_location, count, temp.get());
  } else {
    glUniform2fv(real_location, count, value);
  }
}

void GLES2DecoderImpl::DoUniform3fv(
    GLint fake_location, GLsizei count, const GLfloat* value) {
  GLenum type = 0;
  GLint real_location = -1;
  if (!PrepForSetUniformByLocation(fake_location,
                                   "glUniform3fv",
                                   Program::kUniform3f,
                                   &real_location,
                                   &type,
                                   &count)) {
    return;
  }
  if (type == GL_BOOL_VEC3) {
    GLsizei num_values = count * 3;
    scoped_ptr<GLint[]> temp(new GLint[num_values]);
    for (GLsizei ii = 0; ii < num_values; ++ii) {
      temp[ii] = static_cast<GLint>(value[ii] != 0.0f);
    }
    glUniform3iv(real_location, count, temp.get());
  } else {
    glUniform3fv(real_location, count, value);
  }
}

void GLES2DecoderImpl::DoUniform4fv(
    GLint fake_location, GLsizei count, const GLfloat* value) {
  GLenum type = 0;
  GLint real_location = -1;
  if (!PrepForSetUniformByLocation(fake_location,
                                   "glUniform4fv",
                                   Program::kUniform4f,
                                   &real_location,
                                   &type,
                                   &count)) {
    return;
  }
  if (type == GL_BOOL_VEC4) {
    GLsizei num_values = count * 4;
    scoped_ptr<GLint[]> temp(new GLint[num_values]);
    for (GLsizei ii = 0; ii < num_values; ++ii) {
      temp[ii] = static_cast<GLint>(value[ii] != 0.0f);
    }
    glUniform4iv(real_location, count, temp.get());
  } else {
    glUniform4fv(real_location, count, value);
  }
}

void GLES2DecoderImpl::DoUniform2iv(
    GLint fake_location, GLsizei count, const GLint* value) {
  GLenum type = 0;
  GLint real_location = -1;
  if (!PrepForSetUniformByLocation(fake_location,
                                   "glUniform2iv",
                                   Program::kUniform2i,
                                   &real_location,
                                   &type,
                                   &count)) {
    return;
  }
  glUniform2iv(real_location, count, value);
}

void GLES2DecoderImpl::DoUniform3iv(
    GLint fake_location, GLsizei count, const GLint* value) {
  GLenum type = 0;
  GLint real_location = -1;
  if (!PrepForSetUniformByLocation(fake_location,
                                   "glUniform3iv",
                                   Program::kUniform3i,
                                   &real_location,
                                   &type,
                                   &count)) {
    return;
  }
  glUniform3iv(real_location, count, value);
}

void GLES2DecoderImpl::DoUniform4iv(
    GLint fake_location, GLsizei count, const GLint* value) {
  GLenum type = 0;
  GLint real_location = -1;
  if (!PrepForSetUniformByLocation(fake_location,
                                   "glUniform4iv",
                                   Program::kUniform4i,
                                   &real_location,
                                   &type,
                                   &count)) {
    return;
  }
  glUniform4iv(real_location, count, value);
}

void GLES2DecoderImpl::DoUniformMatrix2fv(
    GLint fake_location, GLsizei count, GLboolean transpose,
    const GLfloat* value) {
  GLenum type = 0;
  GLint real_location = -1;
  if (!PrepForSetUniformByLocation(fake_location,
                                   "glUniformMatrix2fv",
                                   Program::kUniformMatrix2f,
                                   &real_location,
                                   &type,
                                   &count)) {
    return;
  }
  glUniformMatrix2fv(real_location, count, transpose, value);
}

void GLES2DecoderImpl::DoUniformMatrix3fv(
    GLint fake_location, GLsizei count, GLboolean transpose,
    const GLfloat* value) {
  GLenum type = 0;
  GLint real_location = -1;
  if (!PrepForSetUniformByLocation(fake_location,
                                   "glUniformMatrix3fv",
                                   Program::kUniformMatrix3f,
                                   &real_location,
                                   &type,
                                   &count)) {
    return;
  }
  glUniformMatrix3fv(real_location, count, transpose, value);
}

void GLES2DecoderImpl::DoUniformMatrix4fv(
    GLint fake_location, GLsizei count, GLboolean transpose,
    const GLfloat* value) {
  GLenum type = 0;
  GLint real_location = -1;
  if (!PrepForSetUniformByLocation(fake_location,
                                   "glUniformMatrix4fv",
                                   Program::kUniformMatrix4f,
                                   &real_location,
                                   &type,
                                   &count)) {
    return;
  }
  glUniformMatrix4fv(real_location, count, transpose, value);
}

void GLES2DecoderImpl::DoUseProgram(GLuint program_id) {
  GLuint service_id = 0;
  Program* program = NULL;
  if (program_id) {
    program = GetProgramInfoNotShader(program_id, "glUseProgram");
    if (!program) {
      return;
    }
    if (!program->IsValid()) {
      // Program was not linked successfully. (ie, glLinkProgram)
      LOCAL_SET_GL_ERROR(
          GL_INVALID_OPERATION, "glUseProgram", "program not linked");
      return;
    }
    service_id = program->service_id();
  }
  if (state_.current_program.get()) {
    program_manager()->UnuseProgram(shader_manager(),
                                    state_.current_program.get());
  }
  state_.current_program = program;
  LogClientServiceMapping("glUseProgram", program_id, service_id);
  glUseProgram(service_id);
  if (state_.current_program.get()) {
    program_manager()->UseProgram(state_.current_program.get());
    if (workarounds().clear_uniforms_before_first_program_use)
      program_manager()->ClearUniforms(program);
  }
}

void GLES2DecoderImpl::RenderWarning(
    const char* filename, int line, const std::string& msg) {
  logger_.LogMessage(filename, line, std::string("RENDER WARNING: ") + msg);
}

void GLES2DecoderImpl::PerformanceWarning(
    const char* filename, int line, const std::string& msg) {
  logger_.LogMessage(filename, line,
                     std::string("PERFORMANCE WARNING: ") + msg);
}

void GLES2DecoderImpl::DoWillUseTexImageIfNeeded(
    Texture* texture, GLenum textarget) {
  // Image is already in use if texture is attached to a framebuffer.
  if (texture && !texture->IsAttachedToFramebuffer()) {
    gfx::GLImage* image = texture->GetLevelImage(textarget, 0);
    if (image) {
      ScopedGLErrorSuppressor suppressor(
          "GLES2DecoderImpl::DoWillUseTexImageIfNeeded",
          GetErrorState());
      glBindTexture(textarget, texture->service_id());
      image->WillUseTexImage();
      RestoreCurrentTextureBindings(&state_, textarget);
    }
  }
}

void GLES2DecoderImpl::DoDidUseTexImageIfNeeded(
    Texture* texture, GLenum textarget) {
  // Image is still in use if texture is attached to a framebuffer.
  if (texture && !texture->IsAttachedToFramebuffer()) {
    gfx::GLImage* image = texture->GetLevelImage(textarget, 0);
    if (image) {
      ScopedGLErrorSuppressor suppressor(
          "GLES2DecoderImpl::DoDidUseTexImageIfNeeded",
          GetErrorState());
      glBindTexture(textarget, texture->service_id());
      image->DidUseTexImage();
      RestoreCurrentTextureBindings(&state_, textarget);
    }
  }
}

bool GLES2DecoderImpl::PrepareTexturesForRender() {
  DCHECK(state_.current_program.get());
  if (!texture_manager()->HaveUnrenderableTextures() &&
      !texture_manager()->HaveImages()) {
    return true;
  }

  bool textures_set = false;
  const Program::SamplerIndices& sampler_indices =
     state_.current_program->sampler_indices();
  for (size_t ii = 0; ii < sampler_indices.size(); ++ii) {
    const Program::UniformInfo* uniform_info =
        state_.current_program->GetUniformInfo(sampler_indices[ii]);
    DCHECK(uniform_info);
    for (size_t jj = 0; jj < uniform_info->texture_units.size(); ++jj) {
      GLuint texture_unit_index = uniform_info->texture_units[jj];
      if (texture_unit_index < state_.texture_units.size()) {
        TextureUnit& texture_unit = state_.texture_units[texture_unit_index];
        TextureRef* texture_ref =
            texture_unit.GetInfoForSamplerType(uniform_info->type).get();
        GLenum textarget = GetBindTargetForSamplerType(uniform_info->type);
        if (!texture_ref || !texture_manager()->CanRender(texture_ref)) {
          textures_set = true;
          glActiveTexture(GL_TEXTURE0 + texture_unit_index);
          glBindTexture(
              textarget,
              texture_manager()->black_texture_id(uniform_info->type));
          LOCAL_RENDER_WARNING(
              std::string("texture bound to texture unit ") +
              base::IntToString(texture_unit_index) +
              " is not renderable. It maybe non-power-of-2 and have"
              " incompatible texture filtering or is not"
              " 'texture complete'");
          continue;
        }

        if (textarget != GL_TEXTURE_CUBE_MAP) {
          Texture* texture = texture_ref->texture();
          gfx::GLImage* image = texture->GetLevelImage(textarget, 0);
          if (image && !texture->IsAttachedToFramebuffer()) {
            ScopedGLErrorSuppressor suppressor(
                "GLES2DecoderImpl::PrepareTexturesForRender", GetErrorState());
            textures_set = true;
            glActiveTexture(GL_TEXTURE0 + texture_unit_index);
            image->WillUseTexImage();
            continue;
          }
        }
      }
      // else: should this be an error?
    }
  }
  return !textures_set;
}

void GLES2DecoderImpl::RestoreStateForTextures() {
  DCHECK(state_.current_program.get());
  const Program::SamplerIndices& sampler_indices =
      state_.current_program->sampler_indices();
  for (size_t ii = 0; ii < sampler_indices.size(); ++ii) {
    const Program::UniformInfo* uniform_info =
        state_.current_program->GetUniformInfo(sampler_indices[ii]);
    DCHECK(uniform_info);
    for (size_t jj = 0; jj < uniform_info->texture_units.size(); ++jj) {
      GLuint texture_unit_index = uniform_info->texture_units[jj];
      if (texture_unit_index < state_.texture_units.size()) {
        TextureUnit& texture_unit = state_.texture_units[texture_unit_index];
        TextureRef* texture_ref =
            texture_unit.GetInfoForSamplerType(uniform_info->type).get();
        if (!texture_ref || !texture_manager()->CanRender(texture_ref)) {
          glActiveTexture(GL_TEXTURE0 + texture_unit_index);
          // Get the texture_ref info that was previously bound here.
          texture_ref = texture_unit.bind_target == GL_TEXTURE_2D
                            ? texture_unit.bound_texture_2d.get()
                            : texture_unit.bound_texture_cube_map.get();
          glBindTexture(texture_unit.bind_target,
                        texture_ref ? texture_ref->service_id() : 0);
          continue;
        }

        if (texture_unit.bind_target != GL_TEXTURE_CUBE_MAP) {
          Texture* texture = texture_ref->texture();
          gfx::GLImage* image =
              texture->GetLevelImage(texture_unit.bind_target, 0);
          if (image && !texture->IsAttachedToFramebuffer()) {
            ScopedGLErrorSuppressor suppressor(
                "GLES2DecoderImpl::RestoreStateForTextures", GetErrorState());
            glActiveTexture(GL_TEXTURE0 + texture_unit_index);
            image->DidUseTexImage();
            continue;
          }
        }
      }
    }
  }
  // Set the active texture back to whatever the user had it as.
  glActiveTexture(GL_TEXTURE0 + state_.active_texture_unit);
}

bool GLES2DecoderImpl::ClearUnclearedTextures() {
  // Only check if there are some uncleared textures.
  if (!texture_manager()->HaveUnsafeTextures()) {
    return true;
  }

  // 1: Check all textures we are about to render with.
  if (state_.current_program.get()) {
    const Program::SamplerIndices& sampler_indices =
        state_.current_program->sampler_indices();
    for (size_t ii = 0; ii < sampler_indices.size(); ++ii) {
      const Program::UniformInfo* uniform_info =
          state_.current_program->GetUniformInfo(sampler_indices[ii]);
      DCHECK(uniform_info);
      for (size_t jj = 0; jj < uniform_info->texture_units.size(); ++jj) {
        GLuint texture_unit_index = uniform_info->texture_units[jj];
        if (texture_unit_index < state_.texture_units.size()) {
          TextureUnit& texture_unit = state_.texture_units[texture_unit_index];
          TextureRef* texture_ref =
              texture_unit.GetInfoForSamplerType(uniform_info->type).get();
          if (texture_ref && !texture_ref->texture()->SafeToRenderFrom()) {
            if (!texture_manager()->ClearRenderableLevels(this, texture_ref)) {
              return false;
            }
          }
        }
      }
    }
  }
  return true;
}

bool GLES2DecoderImpl::IsDrawValid(
    const char* function_name, GLuint max_vertex_accessed, GLsizei primcount) {
  // NOTE: We specifically do not check current_program->IsValid() because
  // it could never be invalid since glUseProgram would have failed. While
  // glLinkProgram could later mark the program as invalid the previous
  // valid program will still function if it is still the current program.
  if (!state_.current_program.get()) {
    // The program does not exist.
    // But GL says no ERROR.
    LOCAL_RENDER_WARNING("Drawing with no current shader program.");
    return false;
  }

  return state_.vertex_attrib_manager
      ->ValidateBindings(function_name,
                         this,
                         feature_info_.get(),
                         state_.current_program.get(),
                         max_vertex_accessed,
                         primcount);
}

bool GLES2DecoderImpl::SimulateAttrib0(
    const char* function_name, GLuint max_vertex_accessed, bool* simulated) {
  DCHECK(simulated);
  *simulated = false;

  if (gfx::GetGLImplementation() == gfx::kGLImplementationEGLGLES2)
    return true;

  const VertexAttrib* attrib =
      state_.vertex_attrib_manager->GetVertexAttrib(0);
  // If it's enabled or it's not used then we don't need to do anything.
  bool attrib_0_used =
      state_.current_program->GetAttribInfoByLocation(0) != NULL;
  if (attrib->enabled() && attrib_0_used) {
    return true;
  }

  // Make a buffer with a single repeated vec4 value enough to
  // simulate the constant value that is supposed to be here.
  // This is required to emulate GLES2 on GL.
  GLuint num_vertices = max_vertex_accessed + 1;
  uint32 size_needed = 0;

  if (num_vertices == 0 ||
      !SafeMultiplyUint32(num_vertices, sizeof(Vec4), &size_needed) ||
      size_needed > 0x7FFFFFFFU) {
    LOCAL_SET_GL_ERROR(GL_OUT_OF_MEMORY, function_name, "Simulating attrib 0");
    return false;
  }

  LOCAL_PERFORMANCE_WARNING(
      "Attribute 0 is disabled. This has signficant performance penalty");

  LOCAL_COPY_REAL_GL_ERRORS_TO_WRAPPER(function_name);
  glBindBuffer(GL_ARRAY_BUFFER, attrib_0_buffer_id_);

  bool new_buffer = static_cast<GLsizei>(size_needed) > attrib_0_size_;
  if (new_buffer) {
    glBufferData(GL_ARRAY_BUFFER, size_needed, NULL, GL_DYNAMIC_DRAW);
    GLenum error = glGetError();
    if (error != GL_NO_ERROR) {
      LOCAL_SET_GL_ERROR(
          GL_OUT_OF_MEMORY, function_name, "Simulating attrib 0");
      return false;
    }
  }

  const Vec4& value = state_.attrib_values[0];
  if (new_buffer ||
      (attrib_0_used &&
       (!attrib_0_buffer_matches_value_ ||
        (value.v[0] != attrib_0_value_.v[0] ||
         value.v[1] != attrib_0_value_.v[1] ||
         value.v[2] != attrib_0_value_.v[2] ||
         value.v[3] != attrib_0_value_.v[3])))) {
    std::vector<Vec4> temp(num_vertices, value);
    glBufferSubData(GL_ARRAY_BUFFER, 0, size_needed, &temp[0].v[0]);
    attrib_0_buffer_matches_value_ = true;
    attrib_0_value_ = value;
    attrib_0_size_ = size_needed;
  }

  glVertexAttribPointer(0, 4, GL_FLOAT, GL_FALSE, 0, NULL);

  if (attrib->divisor())
    glVertexAttribDivisorANGLE(0, 0);

  *simulated = true;
  return true;
}

void GLES2DecoderImpl::RestoreStateForAttrib(GLuint attrib_index) {
  const VertexAttrib* attrib =
      state_.vertex_attrib_manager->GetVertexAttrib(attrib_index);
  const void* ptr = reinterpret_cast<const void*>(attrib->offset());
  Buffer* buffer = attrib->buffer();
  glBindBuffer(GL_ARRAY_BUFFER, buffer ? buffer->service_id() : 0);
  glVertexAttribPointer(
      attrib_index, attrib->size(), attrib->type(), attrib->normalized(),
      attrib->gl_stride(), ptr);
  if (attrib->divisor())
    glVertexAttribDivisorANGLE(attrib_index, attrib->divisor());
  glBindBuffer(
      GL_ARRAY_BUFFER,
      state_.bound_array_buffer.get() ? state_.bound_array_buffer->service_id()
                                      : 0);

  // Never touch vertex attribute 0's state (in particular, never
  // disable it) when running on desktop GL because it will never be
  // re-enabled.
  if (attrib_index != 0 ||
      gfx::GetGLImplementation() == gfx::kGLImplementationEGLGLES2) {
    if (attrib->enabled()) {
      glEnableVertexAttribArray(attrib_index);
    } else {
      glDisableVertexAttribArray(attrib_index);
    }
  }
}

bool GLES2DecoderImpl::SimulateFixedAttribs(
    const char* function_name,
    GLuint max_vertex_accessed, bool* simulated, GLsizei primcount) {
  DCHECK(simulated);
  *simulated = false;
  if (gfx::GetGLImplementation() == gfx::kGLImplementationEGLGLES2)
    return true;

  if (!state_.vertex_attrib_manager->HaveFixedAttribs()) {
    return true;
  }

  LOCAL_PERFORMANCE_WARNING(
      "GL_FIXED attributes have a signficant performance penalty");

  // NOTE: we could be smart and try to check if a buffer is used
  // twice in 2 different attribs, find the overlapping parts and therefore
  // duplicate the minimum amount of data but this whole code path is not meant
  // to be used normally. It's just here to pass that OpenGL ES 2.0 conformance
  // tests so we just add to the buffer attrib used.

  GLuint elements_needed = 0;
  const VertexAttribManager::VertexAttribList& enabled_attribs =
      state_.vertex_attrib_manager->GetEnabledVertexAttribs();
  for (VertexAttribManager::VertexAttribList::const_iterator it =
       enabled_attribs.begin(); it != enabled_attribs.end(); ++it) {
    const VertexAttrib* attrib = *it;
    const Program::VertexAttrib* attrib_info =
        state_.current_program->GetAttribInfoByLocation(attrib->index());
    GLuint max_accessed = attrib->MaxVertexAccessed(primcount,
                                                    max_vertex_accessed);
    GLuint num_vertices = max_accessed + 1;
    if (num_vertices == 0) {
      LOCAL_SET_GL_ERROR(
          GL_OUT_OF_MEMORY, function_name, "Simulating attrib 0");
      return false;
    }
    if (attrib_info &&
        attrib->CanAccess(max_accessed) &&
        attrib->type() == GL_FIXED) {
      uint32 elements_used = 0;
      if (!SafeMultiplyUint32(num_vertices, attrib->size(), &elements_used) ||
          !SafeAddUint32(elements_needed, elements_used, &elements_needed)) {
        LOCAL_SET_GL_ERROR(
            GL_OUT_OF_MEMORY, function_name, "simulating GL_FIXED attribs");
        return false;
      }
    }
  }

  const uint32 kSizeOfFloat = sizeof(float);  // NOLINT
  uint32 size_needed = 0;
  if (!SafeMultiplyUint32(elements_needed, kSizeOfFloat, &size_needed) ||
      size_needed > 0x7FFFFFFFU) {
    LOCAL_SET_GL_ERROR(
        GL_OUT_OF_MEMORY, function_name, "simulating GL_FIXED attribs");
    return false;
  }

  LOCAL_COPY_REAL_GL_ERRORS_TO_WRAPPER(function_name);

  glBindBuffer(GL_ARRAY_BUFFER, fixed_attrib_buffer_id_);
  if (static_cast<GLsizei>(size_needed) > fixed_attrib_buffer_size_) {
    glBufferData(GL_ARRAY_BUFFER, size_needed, NULL, GL_DYNAMIC_DRAW);
    GLenum error = glGetError();
    if (error != GL_NO_ERROR) {
      LOCAL_SET_GL_ERROR(
          GL_OUT_OF_MEMORY, function_name, "simulating GL_FIXED attribs");
      return false;
    }
  }

  // Copy the elements and convert to float
  GLintptr offset = 0;
  for (VertexAttribManager::VertexAttribList::const_iterator it =
       enabled_attribs.begin(); it != enabled_attribs.end(); ++it) {
    const VertexAttrib* attrib = *it;
    const Program::VertexAttrib* attrib_info =
        state_.current_program->GetAttribInfoByLocation(attrib->index());
    GLuint max_accessed = attrib->MaxVertexAccessed(primcount,
                                                  max_vertex_accessed);
    GLuint num_vertices = max_accessed + 1;
    if (num_vertices == 0) {
      LOCAL_SET_GL_ERROR(
          GL_OUT_OF_MEMORY, function_name, "Simulating attrib 0");
      return false;
    }
    if (attrib_info &&
        attrib->CanAccess(max_accessed) &&
        attrib->type() == GL_FIXED) {
      int num_elements = attrib->size() * kSizeOfFloat;
      int size = num_elements * num_vertices;
      scoped_ptr<float[]> data(new float[size]);
      const int32* src = reinterpret_cast<const int32 *>(
          attrib->buffer()->GetRange(attrib->offset(), size));
      const int32* end = src + num_elements;
      float* dst = data.get();
      while (src != end) {
        *dst++ = static_cast<float>(*src++) / 65536.0f;
      }
      glBufferSubData(GL_ARRAY_BUFFER, offset, size, data.get());
      glVertexAttribPointer(
          attrib->index(), attrib->size(), GL_FLOAT, false, 0,
          reinterpret_cast<GLvoid*>(offset));
      offset += size;
    }
  }
  *simulated = true;
  return true;
}

void GLES2DecoderImpl::RestoreStateForSimulatedFixedAttribs() {
  // There's no need to call glVertexAttribPointer because we shadow all the
  // settings and passing GL_FIXED to it will not work.
  glBindBuffer(
      GL_ARRAY_BUFFER,
      state_.bound_array_buffer.get() ? state_.bound_array_buffer->service_id()
                                      : 0);
}

error::Error GLES2DecoderImpl::DoDrawArrays(
    const char* function_name,
    bool instanced,
    GLenum mode,
    GLint first,
    GLsizei count,
    GLsizei primcount) {
  error::Error error = WillAccessBoundFramebufferForDraw();
  if (error != error::kNoError)
    return error;
  if (!validators_->draw_mode.IsValid(mode)) {
    LOCAL_SET_GL_ERROR_INVALID_ENUM(function_name, mode, "mode");
    return error::kNoError;
  }
  if (count < 0) {
    LOCAL_SET_GL_ERROR(GL_INVALID_VALUE, function_name, "count < 0");
    return error::kNoError;
  }
  if (primcount < 0) {
    LOCAL_SET_GL_ERROR(GL_INVALID_VALUE, function_name, "primcount < 0");
    return error::kNoError;
  }
  if (!CheckBoundFramebuffersValid(function_name)) {
    return error::kNoError;
  }
  // We have to check this here because the prototype for glDrawArrays
  // is GLint not GLsizei.
  if (first < 0) {
    LOCAL_SET_GL_ERROR(GL_INVALID_VALUE, function_name, "first < 0");
    return error::kNoError;
  }

  if (count == 0 || (instanced && primcount == 0)) {
    LOCAL_RENDER_WARNING("Render count or primcount is 0.");
    return error::kNoError;
  }

  GLuint max_vertex_accessed = first + count - 1;
  if (IsDrawValid(function_name, max_vertex_accessed, primcount)) {
    if (!ClearUnclearedTextures()) {
      LOCAL_SET_GL_ERROR(GL_INVALID_VALUE, function_name, "out of memory");
      return error::kNoError;
    }
    bool simulated_attrib_0 = false;
    if (!SimulateAttrib0(
        function_name, max_vertex_accessed, &simulated_attrib_0)) {
      return error::kNoError;
    }
    bool simulated_fixed_attribs = false;
    if (SimulateFixedAttribs(
        function_name, max_vertex_accessed, &simulated_fixed_attribs,
        primcount)) {
      bool textures_set = !PrepareTexturesForRender();
      ApplyDirtyState();
      ScopedRenderTo do_render(framebuffer_state_.bound_draw_framebuffer.get());
      if (!instanced) {
        glDrawArrays(mode, first, count);
      } else {
        glDrawArraysInstancedANGLE(mode, first, count, primcount);
      }
      ProcessPendingQueries();
      if (textures_set) {
        RestoreStateForTextures();
      }
      if (simulated_fixed_attribs) {
        RestoreStateForSimulatedFixedAttribs();
      }
    }
    if (simulated_attrib_0) {
      RestoreStateForAttrib(0);
    }
  }
  return error::kNoError;
}

error::Error GLES2DecoderImpl::HandleDrawArrays(
    uint32 immediate_data_size, const cmds::DrawArrays& c) {
  return DoDrawArrays("glDrawArrays",
                      false,
                      static_cast<GLenum>(c.mode),
                      static_cast<GLint>(c.first),
                      static_cast<GLsizei>(c.count),
                      0);
}

error::Error GLES2DecoderImpl::HandleDrawArraysInstancedANGLE(
    uint32 immediate_data_size, const cmds::DrawArraysInstancedANGLE& c) {
  if (!features().angle_instanced_arrays) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_OPERATION,
        "glDrawArraysInstancedANGLE", "function not available");
    return error::kNoError;
  }
  return DoDrawArrays("glDrawArraysIntancedANGLE",
                      true,
                      static_cast<GLenum>(c.mode),
                      static_cast<GLint>(c.first),
                      static_cast<GLsizei>(c.count),
                      static_cast<GLsizei>(c.primcount));
}

error::Error GLES2DecoderImpl::DoDrawElements(
    const char* function_name,
    bool instanced,
    GLenum mode,
    GLsizei count,
    GLenum type,
    int32 offset,
    GLsizei primcount) {
  error::Error error = WillAccessBoundFramebufferForDraw();
  if (error != error::kNoError)
    return error;
  if (!state_.vertex_attrib_manager->element_array_buffer()) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_OPERATION, function_name, "No element array buffer bound");
    return error::kNoError;
  }

  if (count < 0) {
    LOCAL_SET_GL_ERROR(GL_INVALID_VALUE, function_name, "count < 0");
    return error::kNoError;
  }
  if (offset < 0) {
    LOCAL_SET_GL_ERROR(GL_INVALID_VALUE, function_name, "offset < 0");
    return error::kNoError;
  }
  if (!validators_->draw_mode.IsValid(mode)) {
    LOCAL_SET_GL_ERROR_INVALID_ENUM(function_name, mode, "mode");
    return error::kNoError;
  }
  if (!validators_->index_type.IsValid(type)) {
    LOCAL_SET_GL_ERROR_INVALID_ENUM(function_name, type, "type");
    return error::kNoError;
  }
  if (primcount < 0) {
    LOCAL_SET_GL_ERROR(GL_INVALID_VALUE, function_name, "primcount < 0");
    return error::kNoError;
  }

  if (!CheckBoundFramebuffersValid(function_name)) {
    return error::kNoError;
  }

  if (count == 0 || (instanced && primcount == 0)) {
    return error::kNoError;
  }

  GLuint max_vertex_accessed;
  Buffer* element_array_buffer =
      state_.vertex_attrib_manager->element_array_buffer();

  if (!element_array_buffer->GetMaxValueForRange(
      offset, count, type, &max_vertex_accessed)) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_OPERATION, function_name, "range out of bounds for buffer");
    return error::kNoError;
  }

  if (IsDrawValid(function_name, max_vertex_accessed, primcount)) {
    if (!ClearUnclearedTextures()) {
      LOCAL_SET_GL_ERROR(GL_INVALID_VALUE, function_name, "out of memory");
      return error::kNoError;
    }
    bool simulated_attrib_0 = false;
    if (!SimulateAttrib0(
        function_name, max_vertex_accessed, &simulated_attrib_0)) {
      return error::kNoError;
    }
    bool simulated_fixed_attribs = false;
    if (SimulateFixedAttribs(
        function_name, max_vertex_accessed, &simulated_fixed_attribs,
        primcount)) {
      bool textures_set = !PrepareTexturesForRender();
      ApplyDirtyState();
      // TODO(gman): Refactor to hide these details in BufferManager or
      // VertexAttribManager.
      const GLvoid* indices = reinterpret_cast<const GLvoid*>(offset);
      bool used_client_side_array = false;
      if (element_array_buffer->IsClientSideArray()) {
        used_client_side_array = true;
        glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
        indices = element_array_buffer->GetRange(offset, 0);
      }

      ScopedRenderTo do_render(framebuffer_state_.bound_draw_framebuffer.get());
      if (!instanced) {
        glDrawElements(mode, count, type, indices);
      } else {
        glDrawElementsInstancedANGLE(mode, count, type, indices, primcount);
      }

      if (used_client_side_array) {
        glBindBuffer(GL_ELEMENT_ARRAY_BUFFER,
                     element_array_buffer->service_id());
      }

      ProcessPendingQueries();
      if (textures_set) {
        RestoreStateForTextures();
      }
      if (simulated_fixed_attribs) {
        RestoreStateForSimulatedFixedAttribs();
      }
    }
    if (simulated_attrib_0) {
      RestoreStateForAttrib(0);
    }
  }
  return error::kNoError;
}

error::Error GLES2DecoderImpl::HandleDrawElements(
    uint32 immediate_data_size, const cmds::DrawElements& c) {
  return DoDrawElements("glDrawElements",
                        false,
                        static_cast<GLenum>(c.mode),
                        static_cast<GLsizei>(c.count),
                        static_cast<GLenum>(c.type),
                        static_cast<int32>(c.index_offset),
                        0);
}

error::Error GLES2DecoderImpl::HandleDrawElementsInstancedANGLE(
    uint32 immediate_data_size, const cmds::DrawElementsInstancedANGLE& c) {
  if (!features().angle_instanced_arrays) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_OPERATION,
        "glDrawElementsInstancedANGLE", "function not available");
    return error::kNoError;
  }
  return DoDrawElements("glDrawElementsInstancedANGLE",
                        true,
                        static_cast<GLenum>(c.mode),
                        static_cast<GLsizei>(c.count),
                        static_cast<GLenum>(c.type),
                        static_cast<int32>(c.index_offset),
                        static_cast<GLsizei>(c.primcount));
}

GLuint GLES2DecoderImpl::DoGetMaxValueInBufferCHROMIUM(
    GLuint buffer_id, GLsizei count, GLenum type, GLuint offset) {
  GLuint max_vertex_accessed = 0;
  Buffer* buffer = GetBuffer(buffer_id);
  if (!buffer) {
    // TODO(gman): Should this be a GL error or a command buffer error?
    LOCAL_SET_GL_ERROR(
        GL_INVALID_VALUE, "GetMaxValueInBufferCHROMIUM", "unknown buffer");
  } else {
    if (!buffer->GetMaxValueForRange(
        offset, count, type, &max_vertex_accessed)) {
      // TODO(gman): Should this be a GL error or a command buffer error?
      LOCAL_SET_GL_ERROR(
          GL_INVALID_OPERATION,
          "GetMaxValueInBufferCHROMIUM", "range out of bounds for buffer");
    }
  }
  return max_vertex_accessed;
}

// Calls glShaderSource for the various versions of the ShaderSource command.
// Assumes that data / data_size points to a piece of memory that is in range
// of whatever context it came from (shared memory, immediate memory, bucket
// memory.)
error::Error GLES2DecoderImpl::ShaderSourceHelper(
    GLuint client_id, const char* data, uint32 data_size) {
  std::string str(data, data + data_size);
  Shader* shader = GetShaderInfoNotProgram(client_id, "glShaderSource");
  if (!shader) {
    return error::kNoError;
  }
  // Note: We don't actually call glShaderSource here. We wait until
  // the call to glCompileShader.
  shader->UpdateSource(str.c_str());
  return error::kNoError;
}

error::Error GLES2DecoderImpl::HandleShaderSource(
    uint32 immediate_data_size, const cmds::ShaderSource& c) {
  uint32 data_size = c.data_size;
  const char* data = GetSharedMemoryAs<const char*>(
      c.data_shm_id, c.data_shm_offset, data_size);
  if (!data) {
    return error::kOutOfBounds;
  }
  return ShaderSourceHelper(c.shader, data, data_size);
}

error::Error GLES2DecoderImpl::HandleShaderSourceBucket(
  uint32 immediate_data_size, const cmds::ShaderSourceBucket& c) {
  Bucket* bucket = GetBucket(c.data_bucket_id);
  if (!bucket || bucket->size() == 0) {
    return error::kInvalidArguments;
  }
  return ShaderSourceHelper(
      c.shader, bucket->GetDataAs<const char*>(0, bucket->size() - 1),
      bucket->size() - 1);
}

void GLES2DecoderImpl::DoCompileShader(GLuint client_id) {
  TRACE_EVENT0("gpu", "GLES2DecoderImpl::DoCompileShader");
  Shader* shader = GetShaderInfoNotProgram(client_id, "glCompileShader");
  if (!shader) {
    return;
  }
  ShaderTranslator* translator = NULL;
  if (use_shader_translator_) {
    translator = shader->shader_type() == GL_VERTEX_SHADER ?
        vertex_translator_.get() : fragment_translator_.get();
  }

  program_manager()->DoCompileShader(
     shader,
     translator,
     feature_info_->feature_flags().angle_translated_shader_source ?
         ProgramManager::kANGLE : ProgramManager::kGL);
};

void GLES2DecoderImpl::DoGetShaderiv(
    GLuint shader_id, GLenum pname, GLint* params) {
  Shader* shader = GetShaderInfoNotProgram(shader_id, "glGetShaderiv");
  if (!shader) {
    return;
  }
  switch (pname) {
    case GL_SHADER_SOURCE_LENGTH:
      *params = shader->source() ? shader->source()->size() + 1 : 0;
      return;
    case GL_COMPILE_STATUS:
      *params = compile_shader_always_succeeds_ ? true : shader->IsValid();
      return;
    case GL_INFO_LOG_LENGTH:
      *params = shader->log_info() ? shader->log_info()->size() + 1 : 0;
      return;
    case GL_TRANSLATED_SHADER_SOURCE_LENGTH_ANGLE:
      *params = shader->translated_source() ?
          shader->translated_source()->size() + 1 : 0;
      return;
    default:
      break;
  }
  glGetShaderiv(shader->service_id(), pname, params);
}

error::Error GLES2DecoderImpl::HandleGetShaderSource(
    uint32 immediate_data_size, const cmds::GetShaderSource& c) {
  GLuint shader_id = c.shader;
  uint32 bucket_id = static_cast<uint32>(c.bucket_id);
  Bucket* bucket = CreateBucket(bucket_id);
  Shader* shader = GetShaderInfoNotProgram(shader_id, "glGetShaderSource");
  if (!shader || !shader->source()) {
    bucket->SetSize(0);
    return error::kNoError;
  }
  bucket->SetFromString(shader->source()->c_str());
  return error::kNoError;
}

error::Error GLES2DecoderImpl::HandleGetTranslatedShaderSourceANGLE(
    uint32 immediate_data_size,
    const cmds::GetTranslatedShaderSourceANGLE& c) {
  GLuint shader_id = c.shader;
  uint32 bucket_id = static_cast<uint32>(c.bucket_id);
  Bucket* bucket = CreateBucket(bucket_id);
  Shader* shader = GetShaderInfoNotProgram(
      shader_id, "glGetTranslatedShaderSourceANGLE");
  if (!shader) {
    bucket->SetSize(0);
    return error::kNoError;
  }

  bucket->SetFromString(shader->translated_source() ?
      shader->translated_source()->c_str() : NULL);
  return error::kNoError;
}

error::Error GLES2DecoderImpl::HandleGetProgramInfoLog(
    uint32 immediate_data_size, const cmds::GetProgramInfoLog& c) {
  GLuint program_id = c.program;
  uint32 bucket_id = static_cast<uint32>(c.bucket_id);
  Bucket* bucket = CreateBucket(bucket_id);
  Program* program = GetProgramInfoNotShader(
      program_id, "glGetProgramInfoLog");
  if (!program || !program->log_info()) {
    bucket->SetFromString("");
    return error::kNoError;
  }
  bucket->SetFromString(program->log_info()->c_str());
  return error::kNoError;
}

error::Error GLES2DecoderImpl::HandleGetShaderInfoLog(
    uint32 immediate_data_size, const cmds::GetShaderInfoLog& c) {
  GLuint shader_id = c.shader;
  uint32 bucket_id = static_cast<uint32>(c.bucket_id);
  Bucket* bucket = CreateBucket(bucket_id);
  Shader* shader = GetShaderInfoNotProgram(shader_id, "glGetShaderInfoLog");
  if (!shader || !shader->log_info()) {
    bucket->SetFromString("");
    return error::kNoError;
  }
  bucket->SetFromString(shader->log_info()->c_str());
  return error::kNoError;
}

bool GLES2DecoderImpl::DoIsEnabled(GLenum cap) {
  return state_.GetEnabled(cap);
}

bool GLES2DecoderImpl::DoIsBuffer(GLuint client_id) {
  const Buffer* buffer = GetBuffer(client_id);
  return buffer && buffer->IsValid() && !buffer->IsDeleted();
}

bool GLES2DecoderImpl::DoIsFramebuffer(GLuint client_id) {
  const Framebuffer* framebuffer =
      GetFramebuffer(client_id);
  return framebuffer && framebuffer->IsValid() && !framebuffer->IsDeleted();
}

bool GLES2DecoderImpl::DoIsProgram(GLuint client_id) {
  // IsProgram is true for programs as soon as they are created, until they are
  // deleted and no longer in use.
  const Program* program = GetProgram(client_id);
  return program != NULL && !program->IsDeleted();
}

bool GLES2DecoderImpl::DoIsRenderbuffer(GLuint client_id) {
  const Renderbuffer* renderbuffer =
      GetRenderbuffer(client_id);
  return renderbuffer && renderbuffer->IsValid() && !renderbuffer->IsDeleted();
}

bool GLES2DecoderImpl::DoIsShader(GLuint client_id) {
  // IsShader is true for shaders as soon as they are created, until they
  // are deleted and not attached to any programs.
  const Shader* shader = GetShader(client_id);
  return shader != NULL && !shader->IsDeleted();
}

bool GLES2DecoderImpl::DoIsTexture(GLuint client_id) {
  const TextureRef* texture_ref = GetTexture(client_id);
  return texture_ref && texture_ref->texture()->IsValid();
}

void GLES2DecoderImpl::DoAttachShader(
    GLuint program_client_id, GLint shader_client_id) {
  Program* program = GetProgramInfoNotShader(
      program_client_id, "glAttachShader");
  if (!program) {
    return;
  }
  Shader* shader = GetShaderInfoNotProgram(shader_client_id, "glAttachShader");
  if (!shader) {
    return;
  }
  if (!program->AttachShader(shader_manager(), shader)) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_OPERATION,
        "glAttachShader",
        "can not attach more than one shader of the same type.");
    return;
  }
  glAttachShader(program->service_id(), shader->service_id());
}

void GLES2DecoderImpl::DoDetachShader(
    GLuint program_client_id, GLint shader_client_id) {
  Program* program = GetProgramInfoNotShader(
      program_client_id, "glDetachShader");
  if (!program) {
    return;
  }
  Shader* shader = GetShaderInfoNotProgram(shader_client_id, "glDetachShader");
  if (!shader) {
    return;
  }
  if (!program->DetachShader(shader_manager(), shader)) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_OPERATION,
        "glDetachShader", "shader not attached to program");
    return;
  }
  glDetachShader(program->service_id(), shader->service_id());
}

void GLES2DecoderImpl::DoValidateProgram(GLuint program_client_id) {
  Program* program = GetProgramInfoNotShader(
      program_client_id, "glValidateProgram");
  if (!program) {
    return;
  }
  program->Validate();
}

void GLES2DecoderImpl::GetVertexAttribHelper(
    const VertexAttrib* attrib, GLenum pname, GLint* params) {
  switch (pname) {
    case GL_VERTEX_ATTRIB_ARRAY_BUFFER_BINDING: {
        Buffer* buffer = attrib->buffer();
        if (buffer && !buffer->IsDeleted()) {
          GLuint client_id;
          buffer_manager()->GetClientId(buffer->service_id(), &client_id);
          *params = client_id;
        }
        break;
      }
    case GL_VERTEX_ATTRIB_ARRAY_ENABLED:
      *params = attrib->enabled();
      break;
    case GL_VERTEX_ATTRIB_ARRAY_SIZE:
      *params = attrib->size();
      break;
    case GL_VERTEX_ATTRIB_ARRAY_STRIDE:
      *params = attrib->gl_stride();
      break;
    case GL_VERTEX_ATTRIB_ARRAY_TYPE:
      *params = attrib->type();
      break;
    case GL_VERTEX_ATTRIB_ARRAY_NORMALIZED:
      *params = attrib->normalized();
      break;
    case GL_VERTEX_ATTRIB_ARRAY_DIVISOR_ANGLE:
      *params = attrib->divisor();
      break;
    default:
      NOTREACHED();
      break;
  }
}

void GLES2DecoderImpl::DoGetTexParameterfv(
    GLenum target, GLenum pname, GLfloat* params) {
  InitTextureMaxAnisotropyIfNeeded(target, pname);
  glGetTexParameterfv(target, pname, params);
}

void GLES2DecoderImpl::DoGetTexParameteriv(
    GLenum target, GLenum pname, GLint* params) {
  InitTextureMaxAnisotropyIfNeeded(target, pname);
  glGetTexParameteriv(target, pname, params);
}

void GLES2DecoderImpl::InitTextureMaxAnisotropyIfNeeded(
    GLenum target, GLenum pname) {
  if (!workarounds().init_texture_max_anisotropy)
    return;
  if (pname != GL_TEXTURE_MAX_ANISOTROPY_EXT ||
      !validators_->texture_parameter.IsValid(pname)) {
    return;
  }

  TextureRef* texture_ref = texture_manager()->GetTextureInfoForTarget(
      &state_, target);
  if (!texture_ref) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_OPERATION,
        "glGetTexParamter{fi}v", "unknown texture for target");
    return;
  }
  Texture* texture = texture_ref->texture();
  texture->InitTextureMaxAnisotropyIfNeeded(target);
}

void GLES2DecoderImpl::DoGetVertexAttribfv(
    GLuint index, GLenum pname, GLfloat* params) {
  VertexAttrib* attrib = state_.vertex_attrib_manager->GetVertexAttrib(index);
  if (!attrib) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_VALUE, "glGetVertexAttribfv", "index out of range");
    return;
  }
  switch (pname) {
    case GL_CURRENT_VERTEX_ATTRIB: {
      const Vec4& value = state_.attrib_values[index];
      params[0] = value.v[0];
      params[1] = value.v[1];
      params[2] = value.v[2];
      params[3] = value.v[3];
      break;
    }
    default: {
      GLint value = 0;
      GetVertexAttribHelper(attrib, pname, &value);
      *params = static_cast<GLfloat>(value);
      break;
    }
  }
}

void GLES2DecoderImpl::DoGetVertexAttribiv(
    GLuint index, GLenum pname, GLint* params) {
  VertexAttrib* attrib = state_.vertex_attrib_manager->GetVertexAttrib(index);
  if (!attrib) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_VALUE, "glGetVertexAttribiv", "index out of range");
    return;
  }
  switch (pname) {
    case GL_CURRENT_VERTEX_ATTRIB: {
      const Vec4& value = state_.attrib_values[index];
      params[0] = static_cast<GLint>(value.v[0]);
      params[1] = static_cast<GLint>(value.v[1]);
      params[2] = static_cast<GLint>(value.v[2]);
      params[3] = static_cast<GLint>(value.v[3]);
      break;
    }
    default:
      GetVertexAttribHelper(attrib, pname, params);
      break;
  }
}

bool GLES2DecoderImpl::SetVertexAttribValue(
    const char* function_name, GLuint index, const GLfloat* value) {
  if (index >= state_.attrib_values.size()) {
    LOCAL_SET_GL_ERROR(GL_INVALID_VALUE, function_name, "index out of range");
    return false;
  }
  Vec4& v = state_.attrib_values[index];
  v.v[0] = value[0];
  v.v[1] = value[1];
  v.v[2] = value[2];
  v.v[3] = value[3];
  return true;
}

void GLES2DecoderImpl::DoVertexAttrib1f(GLuint index, GLfloat v0) {
  GLfloat v[4] = { v0, 0.0f, 0.0f, 1.0f, };
  if (SetVertexAttribValue("glVertexAttrib1f", index, v)) {
    glVertexAttrib1f(index, v0);
  }
}

void GLES2DecoderImpl::DoVertexAttrib2f(GLuint index, GLfloat v0, GLfloat v1) {
  GLfloat v[4] = { v0, v1, 0.0f, 1.0f, };
  if (SetVertexAttribValue("glVertexAttrib2f", index, v)) {
    glVertexAttrib2f(index, v0, v1);
  }
}

void GLES2DecoderImpl::DoVertexAttrib3f(
    GLuint index, GLfloat v0, GLfloat v1, GLfloat v2) {
  GLfloat v[4] = { v0, v1, v2, 1.0f, };
  if (SetVertexAttribValue("glVertexAttrib3f", index, v)) {
    glVertexAttrib3f(index, v0, v1, v2);
  }
}

void GLES2DecoderImpl::DoVertexAttrib4f(
    GLuint index, GLfloat v0, GLfloat v1, GLfloat v2, GLfloat v3) {
  GLfloat v[4] = { v0, v1, v2, v3, };
  if (SetVertexAttribValue("glVertexAttrib4f", index, v)) {
    glVertexAttrib4f(index, v0, v1, v2, v3);
  }
}

void GLES2DecoderImpl::DoVertexAttrib1fv(GLuint index, const GLfloat* v) {
  GLfloat t[4] = { v[0], 0.0f, 0.0f, 1.0f, };
  if (SetVertexAttribValue("glVertexAttrib1fv", index, t)) {
    glVertexAttrib1fv(index, v);
  }
}

void GLES2DecoderImpl::DoVertexAttrib2fv(GLuint index, const GLfloat* v) {
  GLfloat t[4] = { v[0], v[1], 0.0f, 1.0f, };
  if (SetVertexAttribValue("glVertexAttrib2fv", index, t)) {
    glVertexAttrib2fv(index, v);
  }
}

void GLES2DecoderImpl::DoVertexAttrib3fv(GLuint index, const GLfloat* v) {
  GLfloat t[4] = { v[0], v[1], v[2], 1.0f, };
  if (SetVertexAttribValue("glVertexAttrib3fv", index, t)) {
    glVertexAttrib3fv(index, v);
  }
}

void GLES2DecoderImpl::DoVertexAttrib4fv(GLuint index, const GLfloat* v) {
  if (SetVertexAttribValue("glVertexAttrib4fv", index, v)) {
    glVertexAttrib4fv(index, v);
  }
}

error::Error GLES2DecoderImpl::HandleVertexAttribPointer(
    uint32 immediate_data_size, const cmds::VertexAttribPointer& c) {

  if (!state_.bound_array_buffer.get() ||
      state_.bound_array_buffer->IsDeleted()) {
    if (state_.vertex_attrib_manager.get() ==
        default_vertex_attrib_manager_.get()) {
      LOCAL_SET_GL_ERROR(
          GL_INVALID_VALUE, "glVertexAttribPointer", "no array buffer bound");
      return error::kNoError;
    } else if (c.offset != 0) {
      LOCAL_SET_GL_ERROR(
          GL_INVALID_VALUE,
          "glVertexAttribPointer", "client side arrays are not allowed");
      return error::kNoError;
    }
  }

  GLuint indx = c.indx;
  GLint size = c.size;
  GLenum type = c.type;
  GLboolean normalized = c.normalized;
  GLsizei stride = c.stride;
  GLsizei offset = c.offset;
  const void* ptr = reinterpret_cast<const void*>(offset);
  if (!validators_->vertex_attrib_type.IsValid(type)) {
    LOCAL_SET_GL_ERROR_INVALID_ENUM("glVertexAttribPointer", type, "type");
    return error::kNoError;
  }
  if (!validators_->vertex_attrib_size.IsValid(size)) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_VALUE, "glVertexAttribPointer", "size GL_INVALID_VALUE");
    return error::kNoError;
  }
  if (indx >= group_->max_vertex_attribs()) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_VALUE, "glVertexAttribPointer", "index out of range");
    return error::kNoError;
  }
  if (stride < 0) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_VALUE, "glVertexAttribPointer", "stride < 0");
    return error::kNoError;
  }
  if (stride > 255) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_VALUE, "glVertexAttribPointer", "stride > 255");
    return error::kNoError;
  }
  if (offset < 0) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_VALUE, "glVertexAttribPointer", "offset < 0");
    return error::kNoError;
  }
  GLsizei component_size =
      GLES2Util::GetGLTypeSizeForTexturesAndBuffers(type);
  if (offset % component_size > 0) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_OPERATION,
        "glVertexAttribPointer", "offset not valid for type");
    return error::kNoError;
  }
  if (stride % component_size > 0) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_OPERATION,
        "glVertexAttribPointer", "stride not valid for type");
    return error::kNoError;
  }
  state_.vertex_attrib_manager
      ->SetAttribInfo(indx,
                      state_.bound_array_buffer.get(),
                      size,
                      type,
                      normalized,
                      stride,
                      stride != 0 ? stride : component_size * size,
                      offset);
  if (type != GL_FIXED) {
    glVertexAttribPointer(indx, size, type, normalized, stride, ptr);
  }
  return error::kNoError;
}

void GLES2DecoderImpl::DoViewport(GLint x, GLint y, GLsizei width,
                                  GLsizei height) {
  state_.viewport_x = x;
  state_.viewport_y = y;
  state_.viewport_width = std::min(width, viewport_max_width_);
  state_.viewport_height = std::min(height, viewport_max_height_);
  glViewport(x, y, width, height);
}

error::Error GLES2DecoderImpl::HandleVertexAttribDivisorANGLE(
    uint32 immediate_data_size, const cmds::VertexAttribDivisorANGLE& c) {
  if (!features().angle_instanced_arrays) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_OPERATION,
        "glVertexAttribDivisorANGLE", "function not available");
  }
  GLuint index = c.index;
  GLuint divisor = c.divisor;
  if (index >= group_->max_vertex_attribs()) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_VALUE,
        "glVertexAttribDivisorANGLE", "index out of range");
    return error::kNoError;
  }

  state_.vertex_attrib_manager->SetDivisor(
      index,
      divisor);
  glVertexAttribDivisorANGLE(index, divisor);
  return error::kNoError;
}

template <typename pixel_data_type>
static void WriteAlphaData(
    void *pixels, uint32 row_count, uint32 channel_count,
    uint32 alpha_channel_index, uint32 unpadded_row_size,
    uint32 padded_row_size, pixel_data_type alpha_value) {
  DCHECK_GT(channel_count, 0U);
  DCHECK_EQ(unpadded_row_size % sizeof(pixel_data_type), 0U);
  uint32 unpadded_row_size_in_elements =
      unpadded_row_size / sizeof(pixel_data_type);
  DCHECK_EQ(padded_row_size % sizeof(pixel_data_type), 0U);
  uint32 padded_row_size_in_elements =
      padded_row_size / sizeof(pixel_data_type);
  pixel_data_type* dst =
      static_cast<pixel_data_type*>(pixels) + alpha_channel_index;
  for (uint32 yy = 0; yy < row_count; ++yy) {
    pixel_data_type* end = dst + unpadded_row_size_in_elements;
    for (pixel_data_type* d = dst; d < end; d += channel_count) {
      *d = alpha_value;
    }
    dst += padded_row_size_in_elements;
  }
}

void GLES2DecoderImpl::FinishReadPixels(
    const cmds::ReadPixels& c,
    GLuint buffer) {
  TRACE_EVENT0("gpu", "GLES2DecoderImpl::FinishReadPixels");
  GLsizei width = c.width;
  GLsizei height = c.height;
  GLenum format = c.format;
  GLenum type = c.type;
  typedef cmds::ReadPixels::Result Result;
  uint32 pixels_size;
  Result* result = NULL;
  if (c.result_shm_id != 0) {
    result = GetSharedMemoryAs<Result*>(
        c.result_shm_id, c.result_shm_offset, sizeof(*result));
    if (!result) {
      if (buffer != 0) {
        glDeleteBuffersARB(1, &buffer);
      }
      return;
    }
  }
  GLES2Util::ComputeImageDataSizes(
      width, height, format, type, state_.pack_alignment, &pixels_size,
      NULL, NULL);
  void* pixels = GetSharedMemoryAs<void*>(
      c.pixels_shm_id, c.pixels_shm_offset, pixels_size);
  if (!pixels) {
    if (buffer != 0) {
      glDeleteBuffersARB(1, &buffer);
    }
    return;
  }

  if (buffer != 0) {
    glBindBuffer(GL_PIXEL_PACK_BUFFER_ARB, buffer);
    void* data;
    if (features().map_buffer_range) {
      data = glMapBufferRange(
          GL_PIXEL_PACK_BUFFER_ARB, 0, pixels_size, GL_MAP_READ_BIT);
    } else {
      data = glMapBuffer(GL_PIXEL_PACK_BUFFER_ARB, GL_READ_ONLY);
    }
    memcpy(pixels, data, pixels_size);
    // GL_PIXEL_PACK_BUFFER_ARB is currently unused, so we don't
    // have to restore the state.
    glUnmapBuffer(GL_PIXEL_PACK_BUFFER_ARB);
    glBindBuffer(GL_PIXEL_PACK_BUFFER_ARB, 0);
    glDeleteBuffersARB(1, &buffer);
  }

  if (result != NULL) {
    *result = true;
  }

  GLenum read_format = GetBoundReadFrameBufferInternalFormat();
  uint32 channels_exist = GLES2Util::GetChannelsForFormat(read_format);
  if ((channels_exist & 0x0008) == 0 &&
      workarounds().clear_alpha_in_readpixels) {
    // Set the alpha to 255 because some drivers are buggy in this regard.
    uint32 temp_size;

    uint32 unpadded_row_size;
    uint32 padded_row_size;
    if (!GLES2Util::ComputeImageDataSizes(
            width, 2, format, type, state_.pack_alignment, &temp_size,
            &unpadded_row_size, &padded_row_size)) {
      return;
    }

    uint32 channel_count = 0;
    uint32 alpha_channel = 0;
    switch (format) {
      case GL_RGBA:
      case GL_BGRA_EXT:
        channel_count = 4;
        alpha_channel = 3;
        break;
      case GL_ALPHA:
        channel_count = 1;
        alpha_channel = 0;
        break;
    }

    if (channel_count > 0) {
      switch (type) {
        case GL_UNSIGNED_BYTE:
          WriteAlphaData<uint8>(
              pixels, height, channel_count, alpha_channel, unpadded_row_size,
              padded_row_size, 0xFF);
          break;
        case GL_FLOAT:
          WriteAlphaData<float>(
              pixels, height, channel_count, alpha_channel, unpadded_row_size,
              padded_row_size, 1.0f);
          break;
        case GL_HALF_FLOAT:
          WriteAlphaData<uint16>(
              pixels, height, channel_count, alpha_channel, unpadded_row_size,
              padded_row_size, 0x3C00);
          break;
      }
    }
  }
}


error::Error GLES2DecoderImpl::HandleReadPixels(
    uint32 immediate_data_size, const cmds::ReadPixels& c) {
  TRACE_EVENT0("gpu", "GLES2DecoderImpl::HandleReadPixels");
  error::Error fbo_error = WillAccessBoundFramebufferForRead();
  if (fbo_error != error::kNoError)
    return fbo_error;
  GLint x = c.x;
  GLint y = c.y;
  GLsizei width = c.width;
  GLsizei height = c.height;
  GLenum format = c.format;
  GLenum type = c.type;
  GLboolean async = c.async;
  if (width < 0 || height < 0) {
    LOCAL_SET_GL_ERROR(GL_INVALID_VALUE, "glReadPixels", "dimensions < 0");
    return error::kNoError;
  }
  typedef cmds::ReadPixels::Result Result;
  uint32 pixels_size;
  if (!GLES2Util::ComputeImageDataSizes(
      width, height, format, type, state_.pack_alignment, &pixels_size,
      NULL, NULL)) {
    return error::kOutOfBounds;
  }
  void* pixels = GetSharedMemoryAs<void*>(
      c.pixels_shm_id, c.pixels_shm_offset, pixels_size);
  if (!pixels) {
    return error::kOutOfBounds;
  }
  Result* result = NULL;
  if (c.result_shm_id != 0) {
    result = GetSharedMemoryAs<Result*>(
        c.result_shm_id, c.result_shm_offset, sizeof(*result));
    if (!result) {
      return error::kOutOfBounds;
    }
  }

  if (!validators_->read_pixel_format.IsValid(format)) {
    LOCAL_SET_GL_ERROR_INVALID_ENUM("glReadPixels", format, "format");
    return error::kNoError;
  }
  if (!validators_->read_pixel_type.IsValid(type)) {
    LOCAL_SET_GL_ERROR_INVALID_ENUM("glReadPixels", type, "type");
    return error::kNoError;
  }
  if ((format != GL_RGBA && format != GL_BGRA_EXT && format != GL_RGB &&
      format != GL_ALPHA) || type != GL_UNSIGNED_BYTE) {
    // format and type are acceptable enums but not guaranteed to be supported
    // for this framebuffer.  Have to ask gl if they are valid.
    GLint preferred_format = 0;
    DoGetIntegerv(GL_IMPLEMENTATION_COLOR_READ_FORMAT, &preferred_format);
    GLint preferred_type = 0;
    DoGetIntegerv(GL_IMPLEMENTATION_COLOR_READ_TYPE, &preferred_type);
    if (format != static_cast<GLenum>(preferred_format) ||
        type != static_cast<GLenum>(preferred_type)) {
      LOCAL_SET_GL_ERROR(
          GL_INVALID_OPERATION, "glReadPixels", "format and type incompatible "
          "with the current read framebuffer");
      return error::kNoError;
    }
  }
  if (width == 0 || height == 0) {
    return error::kNoError;
  }

  // Get the size of the current fbo or backbuffer.
  gfx::Size max_size = GetBoundReadFrameBufferSize();

  int32 max_x;
  int32 max_y;
  if (!SafeAddInt32(x, width, &max_x) || !SafeAddInt32(y, height, &max_y)) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_VALUE, "glReadPixels", "dimensions out of range");
    return error::kNoError;
  }

  if (!CheckBoundFramebuffersValid("glReadPixels")) {
    return error::kNoError;
  }

  LOCAL_COPY_REAL_GL_ERRORS_TO_WRAPPER("glReadPixels");

  ScopedResolvedFrameBufferBinder binder(this, false, true);

  if (x < 0 || y < 0 || max_x > max_size.width() || max_y > max_size.height()) {
    // The user requested an out of range area. Get the results 1 line
    // at a time.
    uint32 temp_size;
    uint32 unpadded_row_size;
    uint32 padded_row_size;
    if (!GLES2Util::ComputeImageDataSizes(
        width, 2, format, type, state_.pack_alignment, &temp_size,
        &unpadded_row_size, &padded_row_size)) {
      LOCAL_SET_GL_ERROR(
          GL_INVALID_VALUE, "glReadPixels", "dimensions out of range");
      return error::kNoError;
    }

    GLint dest_x_offset = std::max(-x, 0);
    uint32 dest_row_offset;
    if (!GLES2Util::ComputeImageDataSizes(
        dest_x_offset, 1, format, type, state_.pack_alignment, &dest_row_offset,
        NULL, NULL)) {
      LOCAL_SET_GL_ERROR(
          GL_INVALID_VALUE, "glReadPixels", "dimensions out of range");
      return error::kNoError;
    }

    // Copy each row into the larger dest rect.
    int8* dst = static_cast<int8*>(pixels);
    GLint read_x = std::max(0, x);
    GLint read_end_x = std::max(0, std::min(max_size.width(), max_x));
    GLint read_width = read_end_x - read_x;
    for (GLint yy = 0; yy < height; ++yy) {
      GLint ry = y + yy;

      // Clear the row.
      memset(dst, 0, unpadded_row_size);

      // If the row is in range, copy it.
      if (ry >= 0 && ry < max_size.height() && read_width > 0) {
        glReadPixels(
            read_x, ry, read_width, 1, format, type, dst + dest_row_offset);
      }
      dst += padded_row_size;
    }
  } else {
    if (async && features().use_async_readpixels) {
      GLuint buffer;
      glGenBuffersARB(1, &buffer);
      glBindBuffer(GL_PIXEL_PACK_BUFFER_ARB, buffer);
      glBufferData(GL_PIXEL_PACK_BUFFER_ARB, pixels_size, NULL, GL_STREAM_READ);
      GLenum error = glGetError();
      if (error == GL_NO_ERROR) {
        glReadPixels(x, y, width, height, format, type, 0);
        pending_readpixel_fences_.push(linked_ptr<FenceCallback>(
            new FenceCallback()));
        WaitForReadPixels(base::Bind(
            &GLES2DecoderImpl::FinishReadPixels,
            base::internal::SupportsWeakPtrBase::StaticAsWeakPtr
            <GLES2DecoderImpl>(this),
            c, buffer));
        glBindBuffer(GL_PIXEL_PACK_BUFFER_ARB, 0);
        return error::kNoError;
      } else {
        // On error, unbind pack buffer and fall through to sync readpixels
        glBindBuffer(GL_PIXEL_PACK_BUFFER_ARB, 0);
      }
    }
    glReadPixels(x, y, width, height, format, type, pixels);
  }
  GLenum error = LOCAL_PEEK_GL_ERROR("glReadPixels");
  if (error == GL_NO_ERROR) {
    if (result != NULL) {
      *result = true;
    }
    FinishReadPixels(c, 0);
  }

  return error::kNoError;
}

error::Error GLES2DecoderImpl::HandlePixelStorei(
    uint32 immediate_data_size, const cmds::PixelStorei& c) {
  GLenum pname = c.pname;
  GLenum param = c.param;
  if (!validators_->pixel_store.IsValid(pname)) {
    LOCAL_SET_GL_ERROR_INVALID_ENUM("glPixelStorei", pname, "pname");
    return error::kNoError;
  }
  switch (pname) {
    case GL_PACK_ALIGNMENT:
    case GL_UNPACK_ALIGNMENT:
        if (!validators_->pixel_store_alignment.IsValid(param)) {
            LOCAL_SET_GL_ERROR(
                GL_INVALID_VALUE, "glPixelStorei", "param GL_INVALID_VALUE");
            return error::kNoError;
        }
        break;
    case GL_UNPACK_FLIP_Y_CHROMIUM:
        unpack_flip_y_ = (param != 0);
        return error::kNoError;
    case GL_UNPACK_PREMULTIPLY_ALPHA_CHROMIUM:
        unpack_premultiply_alpha_ = (param != 0);
        return error::kNoError;
    case GL_UNPACK_UNPREMULTIPLY_ALPHA_CHROMIUM:
        unpack_unpremultiply_alpha_ = (param != 0);
        return error::kNoError;
    default:
        break;
  }
  glPixelStorei(pname, param);
  switch (pname) {
    case GL_PACK_ALIGNMENT:
        state_.pack_alignment = param;
        break;
    case GL_PACK_REVERSE_ROW_ORDER_ANGLE:
        state_.pack_reverse_row_order = (param != 0);
        break;
    case GL_UNPACK_ALIGNMENT:
        state_.unpack_alignment = param;
        break;
    default:
        // Validation should have prevented us from getting here.
        NOTREACHED();
        break;
  }
  return error::kNoError;
}

error::Error GLES2DecoderImpl::HandlePostSubBufferCHROMIUM(
    uint32 immediate_data_size, const cmds::PostSubBufferCHROMIUM& c) {
  TRACE_EVENT0("gpu", "GLES2DecoderImpl::HandlePostSubBufferCHROMIUM");
  if (!supports_post_sub_buffer_) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_OPERATION,
        "glPostSubBufferCHROMIUM", "command not supported by surface");
    return error::kNoError;
  }
  bool is_tracing;
  TRACE_EVENT_CATEGORY_GROUP_ENABLED(TRACE_DISABLED_BY_DEFAULT("gpu.debug"),
                                     &is_tracing);
  if (is_tracing) {
    bool is_offscreen = !!offscreen_target_frame_buffer_.get();
    ScopedFrameBufferBinder binder(this, GetBackbufferServiceId());
    gpu_state_tracer_->TakeSnapshotWithCurrentFramebuffer(
        is_offscreen ? offscreen_size_ : surface_->GetSize());
  }
  if (surface_->PostSubBuffer(c.x, c.y, c.width, c.height)) {
    return error::kNoError;
  } else {
    LOG(ERROR) << "Context lost because PostSubBuffer failed.";
    return error::kLostContext;
  }
}

error::Error GLES2DecoderImpl::GetAttribLocationHelper(
    GLuint client_id, uint32 location_shm_id, uint32 location_shm_offset,
    const std::string& name_str) {
  if (!StringIsValidForGLES(name_str.c_str())) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_VALUE, "glGetAttribLocation", "Invalid character");
    return error::kNoError;
  }
  Program* program = GetProgramInfoNotShader(
      client_id, "glGetAttribLocation");
  if (!program) {
    return error::kNoError;
  }
  if (!program->IsValid()) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_OPERATION, "glGetAttribLocation", "program not linked");
    return error::kNoError;
  }
  GLint* location = GetSharedMemoryAs<GLint*>(
      location_shm_id, location_shm_offset, sizeof(GLint));
  if (!location) {
    return error::kOutOfBounds;
  }
  // Require the client to init this incase the context is lost and we are no
  // longer executing commands.
  if (*location != -1) {
    return error::kGenericError;
  }
  *location = program->GetAttribLocation(name_str);
  return error::kNoError;
}

error::Error GLES2DecoderImpl::HandleGetAttribLocation(
    uint32 immediate_data_size, const cmds::GetAttribLocation& c) {
  uint32 name_size = c.data_size;
  const char* name = GetSharedMemoryAs<const char*>(
      c.name_shm_id, c.name_shm_offset, name_size);
  if (!name) {
    return error::kOutOfBounds;
  }
  String name_str(name, name_size);
  return GetAttribLocationHelper(
    c.program, c.location_shm_id, c.location_shm_offset, name_str);
}

error::Error GLES2DecoderImpl::HandleGetAttribLocationBucket(
    uint32 immediate_data_size, const cmds::GetAttribLocationBucket& c) {
  Bucket* bucket = GetBucket(c.name_bucket_id);
  if (!bucket) {
    return error::kInvalidArguments;
  }
  std::string name_str;
  if (!bucket->GetAsString(&name_str)) {
    return error::kInvalidArguments;
  }
  return GetAttribLocationHelper(
    c.program, c.location_shm_id, c.location_shm_offset, name_str);
}

error::Error GLES2DecoderImpl::GetUniformLocationHelper(
    GLuint client_id, uint32 location_shm_id, uint32 location_shm_offset,
    const std::string& name_str) {
  if (!StringIsValidForGLES(name_str.c_str())) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_VALUE, "glGetUniformLocation", "Invalid character");
    return error::kNoError;
  }
  Program* program = GetProgramInfoNotShader(
      client_id, "glGetUniformLocation");
  if (!program) {
    return error::kNoError;
  }
  if (!program->IsValid()) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_OPERATION, "glGetUniformLocation", "program not linked");
    return error::kNoError;
  }
  GLint* location = GetSharedMemoryAs<GLint*>(
      location_shm_id, location_shm_offset, sizeof(GLint));
  if (!location) {
    return error::kOutOfBounds;
  }
  // Require the client to init this incase the context is lost an we are no
  // longer executing commands.
  if (*location != -1) {
    return error::kGenericError;
  }
  *location = program->GetUniformFakeLocation(name_str);
  return error::kNoError;
}

error::Error GLES2DecoderImpl::HandleGetUniformLocation(
    uint32 immediate_data_size, const cmds::GetUniformLocation& c) {
  uint32 name_size = c.data_size;
  const char* name = GetSharedMemoryAs<const char*>(
      c.name_shm_id, c.name_shm_offset, name_size);
  if (!name) {
    return error::kOutOfBounds;
  }
  String name_str(name, name_size);
  return GetUniformLocationHelper(
    c.program, c.location_shm_id, c.location_shm_offset, name_str);
}

error::Error GLES2DecoderImpl::HandleGetUniformLocationBucket(
    uint32 immediate_data_size, const cmds::GetUniformLocationBucket& c) {
  Bucket* bucket = GetBucket(c.name_bucket_id);
  if (!bucket) {
    return error::kInvalidArguments;
  }
  std::string name_str;
  if (!bucket->GetAsString(&name_str)) {
    return error::kInvalidArguments;
  }
  return GetUniformLocationHelper(
    c.program, c.location_shm_id, c.location_shm_offset, name_str);
}

error::Error GLES2DecoderImpl::HandleGetString(
    uint32 immediate_data_size, const cmds::GetString& c) {
  GLenum name = static_cast<GLenum>(c.name);
  if (!validators_->string_type.IsValid(name)) {
    LOCAL_SET_GL_ERROR_INVALID_ENUM("glGetString", name, "name");
    return error::kNoError;
  }
  const char* str = reinterpret_cast<const char*>(glGetString(name));
  std::string extensions;
  switch (name) {
    case GL_VERSION:
      str = "OpenGL ES 2.0 Chromium";
      break;
    case GL_SHADING_LANGUAGE_VERSION:
      str = "OpenGL ES GLSL ES 1.0 Chromium";
      break;
    case GL_RENDERER:
    case GL_VENDOR:
      // Return the unmasked VENDOR/RENDERER string for WebGL contexts.
      // They are used by WEBGL_debug_renderer_info.
      if (!force_webgl_glsl_validation_)
        str = "Chromium";
      break;
    case GL_EXTENSIONS:
      {
        // For WebGL contexts, strip out the OES derivatives and
        // EXT frag depth extensions if they have not been enabled.
        if (force_webgl_glsl_validation_) {
          extensions = feature_info_->extensions();
          if (!derivatives_explicitly_enabled_) {
            size_t offset = extensions.find(kOESDerivativeExtension);
            if (std::string::npos != offset) {
              extensions.replace(offset, arraysize(kOESDerivativeExtension),
                                 std::string());
            }
          }
          if (!frag_depth_explicitly_enabled_) {
            size_t offset = extensions.find(kEXTFragDepthExtension);
            if (std::string::npos != offset) {
              extensions.replace(offset, arraysize(kEXTFragDepthExtension),
                                 std::string());
            }
          }
          if (!draw_buffers_explicitly_enabled_) {
            size_t offset = extensions.find(kEXTDrawBuffersExtension);
            if (std::string::npos != offset) {
              extensions.replace(offset, arraysize(kEXTDrawBuffersExtension),
                                 std::string());
            }
          }
        } else {
          extensions = feature_info_->extensions().c_str();
        }
        if (supports_post_sub_buffer_)
          extensions += " GL_CHROMIUM_post_sub_buffer";
        str = extensions.c_str();
      }
      break;
    default:
      break;
  }
  Bucket* bucket = CreateBucket(c.bucket_id);
  bucket->SetFromString(str);
  return error::kNoError;
}

error::Error GLES2DecoderImpl::HandleBufferData(
    uint32 immediate_data_size, const cmds::BufferData& c) {
  GLenum target = static_cast<GLenum>(c.target);
  GLsizeiptr size = static_cast<GLsizeiptr>(c.size);
  uint32 data_shm_id = static_cast<uint32>(c.data_shm_id);
  uint32 data_shm_offset = static_cast<uint32>(c.data_shm_offset);
  GLenum usage = static_cast<GLenum>(c.usage);
  const void* data = NULL;
  if (data_shm_id != 0 || data_shm_offset != 0) {
    data = GetSharedMemoryAs<const void*>(data_shm_id, data_shm_offset, size);
    if (!data) {
      return error::kOutOfBounds;
    }
  }
  buffer_manager()->ValidateAndDoBufferData(&state_, target, size, data, usage);
  return error::kNoError;
}

void GLES2DecoderImpl::DoBufferSubData(
  GLenum target, GLintptr offset, GLsizeiptr size, const GLvoid * data) {
  // Just delegate it. Some validation is actually done before this.
  buffer_manager()->ValidateAndDoBufferSubData(
      &state_, target, offset, size, data);
}

bool GLES2DecoderImpl::ClearLevel(
    unsigned service_id,
    unsigned bind_target,
    unsigned target,
    int level,
    unsigned internal_format,
    unsigned format,
    unsigned type,
    int width,
    int height,
    bool is_texture_immutable) {
  uint32 channels = GLES2Util::GetChannelsForFormat(format);
  if (feature_info_->feature_flags().angle_depth_texture &&
      (channels & GLES2Util::kDepth) != 0) {
    // It's a depth format and ANGLE doesn't allow texImage2D or texSubImage2D
    // on depth formats.
    GLuint fb = 0;
    glGenFramebuffersEXT(1, &fb);
    glBindFramebufferEXT(GL_DRAW_FRAMEBUFFER_EXT, fb);

    bool have_stencil = (channels & GLES2Util::kStencil) != 0;
    GLenum attachment = have_stencil ? GL_DEPTH_STENCIL_ATTACHMENT :
                                       GL_DEPTH_ATTACHMENT;

    glFramebufferTexture2DEXT(
        GL_DRAW_FRAMEBUFFER_EXT, attachment, target, service_id, level);
    // ANGLE promises a depth only attachment ok.
    if (glCheckFramebufferStatusEXT(GL_DRAW_FRAMEBUFFER_EXT) !=
        GL_FRAMEBUFFER_COMPLETE) {
      return false;
    }
    glClearStencil(0);
    glStencilMask(-1);
    glClearDepth(1.0f);
    glDepthMask(true);
    glDisable(GL_SCISSOR_TEST);
    glClear(GL_DEPTH_BUFFER_BIT | (have_stencil ? GL_STENCIL_BUFFER_BIT : 0));

    RestoreClearState();

    glDeleteFramebuffersEXT(1, &fb);
    Framebuffer* framebuffer =
        GetFramebufferInfoForTarget(GL_DRAW_FRAMEBUFFER_EXT);
    GLuint fb_service_id =
        framebuffer ? framebuffer->service_id() : GetBackbufferServiceId();
    glBindFramebufferEXT(GL_DRAW_FRAMEBUFFER_EXT, fb_service_id);
    return true;
  }

  static const uint32 kMaxZeroSize = 1024 * 1024 * 4;

  uint32 size;
  uint32 padded_row_size;
  if (!GLES2Util::ComputeImageDataSizes(
          width, height, format, type, state_.unpack_alignment, &size,
          NULL, &padded_row_size)) {
    return false;
  }

  TRACE_EVENT1("gpu", "GLES2DecoderImpl::ClearLevel", "size", size);

  int tile_height;

  if (size > kMaxZeroSize) {
    if (kMaxZeroSize < padded_row_size) {
        // That'd be an awfully large texture.
        return false;
    }
    // We should never have a large total size with a zero row size.
    DCHECK_GT(padded_row_size, 0U);
    tile_height = kMaxZeroSize / padded_row_size;
    if (!GLES2Util::ComputeImageDataSizes(
            width, tile_height, format, type, state_.unpack_alignment, &size,
            NULL, NULL)) {
      return false;
    }
  } else {
    tile_height = height;
  }

  // Assumes the size has already been checked.
  scoped_ptr<char[]> zero(new char[size]);
  memset(zero.get(), 0, size);
  glBindTexture(bind_target, service_id);

  GLint y = 0;
  while (y < height) {
    GLint h = y + tile_height > height ? height - y : tile_height;
    if (is_texture_immutable || h != height) {
      glTexSubImage2D(target, level, 0, y, width, h, format, type, zero.get());
    } else {
      glTexImage2D(
          target, level, internal_format, width, h, 0, format, type,
          zero.get());
    }
    y += tile_height;
  }
  TextureRef* texture = texture_manager()->GetTextureInfoForTarget(
      &state_, bind_target);
  glBindTexture(bind_target, texture ? texture->service_id() : 0);
  return true;
}

namespace {

const int kS3TCBlockWidth = 4;
const int kS3TCBlockHeight = 4;
const int kS3TCDXT1BlockSize = 8;
const int kS3TCDXT3AndDXT5BlockSize = 16;
const int kETC1BlockWidth = 4;
const int kETC1BlockHeight = 4;
const int kETC1BlockSize = 8;

bool IsValidDXTSize(GLint level, GLsizei size) {
  return (size == 1) ||
         (size == 2) || !(size % kS3TCBlockWidth);
}

}  // anonymous namespace.

bool GLES2DecoderImpl::ValidateCompressedTexFuncData(
    const char* function_name,
    GLsizei width, GLsizei height, GLenum format, size_t size) {
  unsigned int bytes_required = 0;

  switch (format) {
    case GL_COMPRESSED_RGB_S3TC_DXT1_EXT:
    case GL_COMPRESSED_RGBA_S3TC_DXT1_EXT: {
        int num_blocks_across =
            (width + kS3TCBlockWidth - 1) / kS3TCBlockWidth;
        int num_blocks_down =
            (height + kS3TCBlockHeight - 1) / kS3TCBlockHeight;
        int num_blocks = num_blocks_across * num_blocks_down;
        bytes_required = num_blocks * kS3TCDXT1BlockSize;
        break;
      }
    case GL_COMPRESSED_RGBA_S3TC_DXT3_EXT:
    case GL_COMPRESSED_RGBA_S3TC_DXT5_EXT: {
        int num_blocks_across =
            (width + kS3TCBlockWidth - 1) / kS3TCBlockWidth;
        int num_blocks_down =
            (height + kS3TCBlockHeight - 1) / kS3TCBlockHeight;
        int num_blocks = num_blocks_across * num_blocks_down;
        bytes_required = num_blocks * kS3TCDXT3AndDXT5BlockSize;
        break;
      }
    case GL_ETC1_RGB8_OES: {
        int num_blocks_across =
            (width + kETC1BlockWidth - 1) / kETC1BlockWidth;
        int num_blocks_down =
            (height + kETC1BlockHeight - 1) / kETC1BlockHeight;
        int num_blocks = num_blocks_across * num_blocks_down;
        bytes_required = num_blocks * kETC1BlockSize;
        break;
      }
    default:
      LOCAL_SET_GL_ERROR_INVALID_ENUM(function_name, format, "format");
      return false;
  }

  if (size != bytes_required) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_VALUE, function_name, "size is not correct for dimensions");
    return false;
  }

  return true;
}

bool GLES2DecoderImpl::ValidateCompressedTexDimensions(
    const char* function_name,
    GLint level, GLsizei width, GLsizei height, GLenum format) {
  switch (format) {
    case GL_COMPRESSED_RGB_S3TC_DXT1_EXT:
    case GL_COMPRESSED_RGBA_S3TC_DXT1_EXT:
    case GL_COMPRESSED_RGBA_S3TC_DXT3_EXT:
    case GL_COMPRESSED_RGBA_S3TC_DXT5_EXT: {
      if (!IsValidDXTSize(level, width) || !IsValidDXTSize(level, height)) {
        LOCAL_SET_GL_ERROR(
            GL_INVALID_OPERATION, function_name,
            "width or height invalid for level");
        return false;
      }
      return true;
    }
    case GL_ETC1_RGB8_OES:
      if (width <= 0 || height <= 0) {
        LOCAL_SET_GL_ERROR(
            GL_INVALID_OPERATION, function_name,
            "width or height invalid for level");
        return false;
      }
      return true;
    default:
      return false;
  }
}

bool GLES2DecoderImpl::ValidateCompressedTexSubDimensions(
    const char* function_name,
    GLenum target, GLint level, GLint xoffset, GLint yoffset,
    GLsizei width, GLsizei height, GLenum format,
    Texture* texture) {
  if (xoffset < 0 || yoffset < 0) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_VALUE, function_name, "xoffset or yoffset < 0");
    return false;
  }

  switch (format) {
    case GL_COMPRESSED_RGB_S3TC_DXT1_EXT:
    case GL_COMPRESSED_RGBA_S3TC_DXT1_EXT:
    case GL_COMPRESSED_RGBA_S3TC_DXT3_EXT:
    case GL_COMPRESSED_RGBA_S3TC_DXT5_EXT: {
      const int kBlockWidth = 4;
      const int kBlockHeight = 4;
      if ((xoffset % kBlockWidth) || (yoffset % kBlockHeight)) {
        LOCAL_SET_GL_ERROR(
            GL_INVALID_OPERATION, function_name,
            "xoffset or yoffset not multiple of 4");
        return false;
      }
      GLsizei tex_width = 0;
      GLsizei tex_height = 0;
      if (!texture->GetLevelSize(target, level, &tex_width, &tex_height) ||
          width - xoffset > tex_width ||
          height - yoffset > tex_height) {
        LOCAL_SET_GL_ERROR(
            GL_INVALID_OPERATION, function_name, "dimensions out of range");
        return false;
      }
      return ValidateCompressedTexDimensions(
          function_name, level, width, height, format);
    }
    case GL_ETC1_RGB8_OES: {
      LOCAL_SET_GL_ERROR(
          GL_INVALID_OPERATION, function_name,
          "not supported for ECT1_RGB8_OES textures");
      return false;
    }
    default:
      return false;
  }
}

error::Error GLES2DecoderImpl::DoCompressedTexImage2D(
  GLenum target,
  GLint level,
  GLenum internal_format,
  GLsizei width,
  GLsizei height,
  GLint border,
  GLsizei image_size,
  const void* data) {
  // TODO(gman): Validate image_size is correct for width, height and format.
  if (!validators_->texture_target.IsValid(target)) {
    LOCAL_SET_GL_ERROR_INVALID_ENUM(
        "glCompressedTexImage2D", target, "target");
    return error::kNoError;
  }
  if (!validators_->compressed_texture_format.IsValid(
      internal_format)) {
    LOCAL_SET_GL_ERROR_INVALID_ENUM(
        "glCompressedTexImage2D", internal_format, "internal_format");
    return error::kNoError;
  }
  if (!texture_manager()->ValidForTarget(target, level, width, height, 1) ||
      border != 0) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_VALUE,
        "glCompressedTexImage2D", "dimensions out of range");
    return error::kNoError;
  }
  TextureRef* texture_ref = texture_manager()->GetTextureInfoForTarget(
      &state_, target);
  if (!texture_ref) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_VALUE,
        "glCompressedTexImage2D", "unknown texture target");
    return error::kNoError;
  }
  Texture* texture = texture_ref->texture();
  if (texture->IsImmutable()) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_OPERATION,
        "glCompressedTexImage2D", "texture is immutable");
    return error::kNoError;
  }

  if (!ValidateCompressedTexDimensions(
      "glCompressedTexImage2D", level, width, height, internal_format) ||
      !ValidateCompressedTexFuncData(
      "glCompressedTexImage2D", width, height, internal_format, image_size)) {
    return error::kNoError;
  }

  if (!EnsureGPUMemoryAvailable(image_size)) {
    LOCAL_SET_GL_ERROR(
        GL_OUT_OF_MEMORY, "glCompressedTexImage2D", "out of memory");
    return error::kNoError;
  }

  if (texture->IsAttachedToFramebuffer()) {
    framebuffer_state_.clear_state_dirty = true;
  }

  scoped_ptr<int8[]> zero;
  if (!data) {
    zero.reset(new int8[image_size]);
    memset(zero.get(), 0, image_size);
    data = zero.get();
  }
  LOCAL_COPY_REAL_GL_ERRORS_TO_WRAPPER("glCompressedTexImage2D");
  glCompressedTexImage2D(
      target, level, internal_format, width, height, border, image_size, data);
  GLenum error = LOCAL_PEEK_GL_ERROR("glCompressedTexImage2D");
  if (error == GL_NO_ERROR) {
    texture_manager()->SetLevelInfo(
        texture_ref, target, level, internal_format,
        width, height, 1, border, 0, 0, true);
  }
  return error::kNoError;
}

error::Error GLES2DecoderImpl::HandleCompressedTexImage2D(
    uint32 immediate_data_size, const cmds::CompressedTexImage2D& c) {
  GLenum target = static_cast<GLenum>(c.target);
  GLint level = static_cast<GLint>(c.level);
  GLenum internal_format = static_cast<GLenum>(c.internalformat);
  GLsizei width = static_cast<GLsizei>(c.width);
  GLsizei height = static_cast<GLsizei>(c.height);
  GLint border = static_cast<GLint>(c.border);
  GLsizei image_size = static_cast<GLsizei>(c.imageSize);
  uint32 data_shm_id = static_cast<uint32>(c.data_shm_id);
  uint32 data_shm_offset = static_cast<uint32>(c.data_shm_offset);
  const void* data = NULL;
  if (data_shm_id != 0 || data_shm_offset != 0) {
    data = GetSharedMemoryAs<const void*>(
        data_shm_id, data_shm_offset, image_size);
    if (!data) {
      return error::kOutOfBounds;
    }
  }
  return DoCompressedTexImage2D(
      target, level, internal_format, width, height, border, image_size, data);
}

error::Error GLES2DecoderImpl::HandleCompressedTexImage2DBucket(
    uint32 immediate_data_size, const cmds::CompressedTexImage2DBucket& c) {
  GLenum target = static_cast<GLenum>(c.target);
  GLint level = static_cast<GLint>(c.level);
  GLenum internal_format = static_cast<GLenum>(c.internalformat);
  GLsizei width = static_cast<GLsizei>(c.width);
  GLsizei height = static_cast<GLsizei>(c.height);
  GLint border = static_cast<GLint>(c.border);
  Bucket* bucket = GetBucket(c.bucket_id);
  if (!bucket) {
    return error::kInvalidArguments;
  }
  uint32 data_size = bucket->size();
  GLsizei imageSize = data_size;
  const void* data = bucket->GetData(0, data_size);
  if (!data) {
    return error::kInvalidArguments;
  }
  return DoCompressedTexImage2D(
      target, level, internal_format, width, height, border,
      imageSize, data);
}

error::Error GLES2DecoderImpl::HandleCompressedTexSubImage2DBucket(
    uint32 immediate_data_size,
    const cmds::CompressedTexSubImage2DBucket& c) {
  GLenum target = static_cast<GLenum>(c.target);
  GLint level = static_cast<GLint>(c.level);
  GLint xoffset = static_cast<GLint>(c.xoffset);
  GLint yoffset = static_cast<GLint>(c.yoffset);
  GLsizei width = static_cast<GLsizei>(c.width);
  GLsizei height = static_cast<GLsizei>(c.height);
  GLenum format = static_cast<GLenum>(c.format);
  Bucket* bucket = GetBucket(c.bucket_id);
  if (!bucket) {
    return error::kInvalidArguments;
  }
  uint32 data_size = bucket->size();
  GLsizei imageSize = data_size;
  const void* data = bucket->GetData(0, data_size);
  if (!data) {
    return error::kInvalidArguments;
  }
  if (!validators_->texture_target.IsValid(target)) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_ENUM, "glCompressedTexSubImage2D", "target");
    return error::kNoError;
  }
  if (!validators_->compressed_texture_format.IsValid(format)) {
    LOCAL_SET_GL_ERROR_INVALID_ENUM(
        "glCompressedTexSubImage2D", format, "format");
    return error::kNoError;
  }
  if (width < 0) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_VALUE, "glCompressedTexSubImage2D", "width < 0");
    return error::kNoError;
  }
  if (height < 0) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_VALUE, "glCompressedTexSubImage2D", "height < 0");
    return error::kNoError;
  }
  if (imageSize < 0) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_VALUE, "glCompressedTexSubImage2D", "imageSize < 0");
    return error::kNoError;
  }
  DoCompressedTexSubImage2D(
      target, level, xoffset, yoffset, width, height, format, imageSize, data);
  return error::kNoError;
}

error::Error GLES2DecoderImpl::HandleTexImage2D(
    uint32 immediate_data_size, const cmds::TexImage2D& c) {
  TRACE_EVENT0("gpu", "GLES2DecoderImpl::HandleTexImage2D");
  // Set as failed for now, but if it successed, this will be set to not failed.
  texture_state_.tex_image_2d_failed = true;
  GLenum target = static_cast<GLenum>(c.target);
  GLint level = static_cast<GLint>(c.level);
  // TODO(kloveless): Change TexImage2D command to use unsigned integer
  // for internalformat.
  GLenum internal_format = static_cast<GLenum>(c.internalformat);
  GLsizei width = static_cast<GLsizei>(c.width);
  GLsizei height = static_cast<GLsizei>(c.height);
  GLint border = static_cast<GLint>(c.border);
  GLenum format = static_cast<GLenum>(c.format);
  GLenum type = static_cast<GLenum>(c.type);
  uint32 pixels_shm_id = static_cast<uint32>(c.pixels_shm_id);
  uint32 pixels_shm_offset = static_cast<uint32>(c.pixels_shm_offset);
  uint32 pixels_size;
  if (!GLES2Util::ComputeImageDataSizes(
      width, height, format, type, state_.unpack_alignment, &pixels_size, NULL,
      NULL)) {
    return error::kOutOfBounds;
  }
  const void* pixels = NULL;
  if (pixels_shm_id != 0 || pixels_shm_offset != 0) {
    pixels = GetSharedMemoryAs<const void*>(
        pixels_shm_id, pixels_shm_offset, pixels_size);
    if (!pixels) {
      return error::kOutOfBounds;
    }
  }

  TextureManager::DoTextImage2DArguments args = {
    target, level, internal_format, width, height, border, format, type,
    pixels, pixels_size};
  texture_manager()->ValidateAndDoTexImage2D(
      &texture_state_, &state_, &framebuffer_state_, args);
  return error::kNoError;
}

void GLES2DecoderImpl::DoCompressedTexSubImage2D(
  GLenum target,
  GLint level,
  GLint xoffset,
  GLint yoffset,
  GLsizei width,
  GLsizei height,
  GLenum format,
  GLsizei image_size,
  const void * data) {
  TextureRef* texture_ref = texture_manager()->GetTextureInfoForTarget(
      &state_, target);
  if (!texture_ref) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_OPERATION,
        "glCompressedTexSubImage2D", "unknown texture for target");
    return;
  }
  Texture* texture = texture_ref->texture();
  GLenum type = 0;
  GLenum internal_format = 0;
  if (!texture->GetLevelType(target, level, &type, &internal_format)) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_OPERATION,
        "glCompressedTexSubImage2D", "level does not exist.");
    return;
  }
  if (internal_format != format) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_OPERATION,
        "glCompressedTexSubImage2D", "format does not match internal format.");
    return;
  }
  if (!texture->ValidForTexture(
      target, level, xoffset, yoffset, width, height, type)) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_VALUE, "glCompressedTexSubImage2D", "bad dimensions.");
    return;
  }

  if (!ValidateCompressedTexFuncData(
      "glCompressedTexSubImage2D", width, height, format, image_size) ||
      !ValidateCompressedTexSubDimensions(
      "glCompressedTexSubImage2D",
      target, level, xoffset, yoffset, width, height, format, texture)) {
    return;
  }


  // Note: There is no need to deal with texture cleared tracking here
  // because the validation above means you can only get here if the level
  // is already a matching compressed format and in that case
  // CompressedTexImage2D already cleared the texture.
  glCompressedTexSubImage2D(
      target, level, xoffset, yoffset, width, height, format, image_size, data);
}

static void Clip(
    GLint start, GLint range, GLint sourceRange,
    GLint* out_start, GLint* out_range) {
  DCHECK(out_start);
  DCHECK(out_range);
  if (start < 0) {
    range += start;
    start = 0;
  }
  GLint end = start + range;
  if (end > sourceRange) {
    range -= end - sourceRange;
  }
  *out_start = start;
  *out_range = range;
}

void GLES2DecoderImpl::DoCopyTexImage2D(
    GLenum target,
    GLint level,
    GLenum internal_format,
    GLint x,
    GLint y,
    GLsizei width,
    GLsizei height,
    GLint border) {
  DCHECK(!ShouldDeferReads());
  TextureRef* texture_ref = texture_manager()->GetTextureInfoForTarget(
      &state_, target);
  if (!texture_ref) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_OPERATION,
        "glCopyTexImage2D", "unknown texture for target");
    return;
  }
  Texture* texture = texture_ref->texture();
  if (texture->IsImmutable()) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_OPERATION, "glCopyTexImage2D", "texture is immutable");
  }
  if (!texture_manager()->ValidForTarget(target, level, width, height, 1) ||
      border != 0) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_VALUE, "glCopyTexImage2D", "dimensions out of range");
    return;
  }
  if (!texture_manager()->ValidateFormatAndTypeCombination(
      state_.GetErrorState(), "glCopyTexImage2D", internal_format,
      GL_UNSIGNED_BYTE)) {
    return;
  }

  // Check we have compatible formats.
  GLenum read_format = GetBoundReadFrameBufferInternalFormat();
  uint32 channels_exist = GLES2Util::GetChannelsForFormat(read_format);
  uint32 channels_needed = GLES2Util::GetChannelsForFormat(internal_format);

  if ((channels_needed & channels_exist) != channels_needed) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_OPERATION, "glCopyTexImage2D", "incompatible format");
    return;
  }

  if ((channels_needed & (GLES2Util::kDepth | GLES2Util::kStencil)) != 0) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_OPERATION,
        "glCopyTexImage2D", "can not be used with depth or stencil textures");
    return;
  }

  uint32 estimated_size = 0;
  if (!GLES2Util::ComputeImageDataSizes(
      width, height, internal_format, GL_UNSIGNED_BYTE, state_.unpack_alignment,
      &estimated_size, NULL, NULL)) {
    LOCAL_SET_GL_ERROR(
        GL_OUT_OF_MEMORY, "glCopyTexImage2D", "dimensions too large");
    return;
  }

  if (!EnsureGPUMemoryAvailable(estimated_size)) {
    LOCAL_SET_GL_ERROR(GL_OUT_OF_MEMORY, "glCopyTexImage2D", "out of memory");
    return;
  }

  if (!CheckBoundFramebuffersValid("glCopyTexImage2D")) {
    return;
  }

  LOCAL_COPY_REAL_GL_ERRORS_TO_WRAPPER("glCopyTexImage2D");
  ScopedResolvedFrameBufferBinder binder(this, false, true);
  gfx::Size size = GetBoundReadFrameBufferSize();

  if (texture->IsAttachedToFramebuffer()) {
    framebuffer_state_.clear_state_dirty = true;
  }

  // Clip to size to source dimensions
  GLint copyX = 0;
  GLint copyY = 0;
  GLint copyWidth = 0;
  GLint copyHeight = 0;
  Clip(x, width, size.width(), &copyX, &copyWidth);
  Clip(y, height, size.height(), &copyY, &copyHeight);

  if (copyX != x ||
      copyY != y ||
      copyWidth != width ||
      copyHeight != height) {
    // some part was clipped so clear the texture.
    if (!ClearLevel(
        texture->service_id(), texture->target(),
        target, level, internal_format, internal_format, GL_UNSIGNED_BYTE,
        width, height, texture->IsImmutable())) {
      LOCAL_SET_GL_ERROR(
          GL_OUT_OF_MEMORY, "glCopyTexImage2D", "dimensions too big");
      return;
    }
    if (copyHeight > 0 && copyWidth > 0) {
      GLint dx = copyX - x;
      GLint dy = copyY - y;
      GLint destX = dx;
      GLint destY = dy;
      ScopedModifyPixels modify(texture_ref);
      glCopyTexSubImage2D(target, level,
                          destX, destY, copyX, copyY,
                          copyWidth, copyHeight);
    }
  } else {
    ScopedModifyPixels modify(texture_ref);
    glCopyTexImage2D(target, level, internal_format,
                     copyX, copyY, copyWidth, copyHeight, border);
  }
  GLenum error = LOCAL_PEEK_GL_ERROR("glCopyTexImage2D");
  if (error == GL_NO_ERROR) {
    texture_manager()->SetLevelInfo(
        texture_ref, target, level, internal_format, width, height, 1,
        border, internal_format, GL_UNSIGNED_BYTE, true);
  }
}

void GLES2DecoderImpl::DoCopyTexSubImage2D(
    GLenum target,
    GLint level,
    GLint xoffset,
    GLint yoffset,
    GLint x,
    GLint y,
    GLsizei width,
    GLsizei height) {
  DCHECK(!ShouldDeferReads());
  TextureRef* texture_ref = texture_manager()->GetTextureInfoForTarget(
      &state_, target);
  if (!texture_ref) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_OPERATION,
        "glCopyTexSubImage2D", "unknown texture for target");
    return;
  }
  Texture* texture = texture_ref->texture();
  GLenum type = 0;
  GLenum format = 0;
  if (!texture->GetLevelType(target, level, &type, &format) ||
      !texture->ValidForTexture(
          target, level, xoffset, yoffset, width, height, type)) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_VALUE, "glCopyTexSubImage2D", "bad dimensions.");
    return;
  }
  if (async_pixel_transfer_manager_->AsyncTransferIsInProgress(texture_ref)) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_OPERATION,
        "glCopyTexSubImage2D", "async upload pending for texture");
    return;
  }

  // Check we have compatible formats.
  GLenum read_format = GetBoundReadFrameBufferInternalFormat();
  uint32 channels_exist = GLES2Util::GetChannelsForFormat(read_format);
  uint32 channels_needed = GLES2Util::GetChannelsForFormat(format);

  if (!channels_needed ||
      (channels_needed & channels_exist) != channels_needed) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_OPERATION, "glCopyTexSubImage2D", "incompatible format");
    return;
  }

  if ((channels_needed & (GLES2Util::kDepth | GLES2Util::kStencil)) != 0) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_OPERATION,
        "glCopySubImage2D", "can not be used with depth or stencil textures");
    return;
  }

  if (!CheckBoundFramebuffersValid("glCopyTexSubImage2D")) {
    return;
  }

  ScopedResolvedFrameBufferBinder binder(this, false, true);
  gfx::Size size = GetBoundReadFrameBufferSize();
  GLint copyX = 0;
  GLint copyY = 0;
  GLint copyWidth = 0;
  GLint copyHeight = 0;
  Clip(x, width, size.width(), &copyX, &copyWidth);
  Clip(y, height, size.height(), &copyY, &copyHeight);

  if (!texture_manager()->ClearTextureLevel(this, texture_ref, target, level)) {
    LOCAL_SET_GL_ERROR(
        GL_OUT_OF_MEMORY, "glCopyTexSubImage2D", "dimensions too big");
    return;
  }

  if (copyX != x ||
      copyY != y ||
      copyWidth != width ||
      copyHeight != height) {
    // some part was clipped so clear the sub rect.
    uint32 pixels_size = 0;
    if (!GLES2Util::ComputeImageDataSizes(
        width, height, format, type, state_.unpack_alignment, &pixels_size,
        NULL, NULL)) {
      LOCAL_SET_GL_ERROR(
          GL_INVALID_VALUE, "glCopyTexSubImage2D", "dimensions too large");
      return;
    }
    scoped_ptr<char[]> zero(new char[pixels_size]);
    memset(zero.get(), 0, pixels_size);
    ScopedModifyPixels modify(texture_ref);
    glTexSubImage2D(
        target, level, xoffset, yoffset, width, height,
        format, type, zero.get());
  }

  if (copyHeight > 0 && copyWidth > 0) {
    GLint dx = copyX - x;
    GLint dy = copyY - y;
    GLint destX = xoffset + dx;
    GLint destY = yoffset + dy;
    ScopedModifyPixels modify(texture_ref);
    glCopyTexSubImage2D(target, level,
                        destX, destY, copyX, copyY,
                        copyWidth, copyHeight);
  }
}

bool GLES2DecoderImpl::ValidateTexSubImage2D(
    error::Error* error,
    const char* function_name,
    GLenum target,
    GLint level,
    GLint xoffset,
    GLint yoffset,
    GLsizei width,
    GLsizei height,
    GLenum format,
    GLenum type,
    const void * data) {
  (*error) = error::kNoError;
  if (!validators_->texture_target.IsValid(target)) {
    LOCAL_SET_GL_ERROR_INVALID_ENUM(function_name, target, "target");
    return false;
  }
  if (width < 0) {
    LOCAL_SET_GL_ERROR(GL_INVALID_VALUE, function_name, "width < 0");
    return false;
  }
  if (height < 0) {
    LOCAL_SET_GL_ERROR(GL_INVALID_VALUE, function_name, "height < 0");
    return false;
  }
  TextureRef* texture_ref = texture_manager()->GetTextureInfoForTarget(
      &state_, target);
  if (!texture_ref) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_OPERATION,
        function_name, "unknown texture for target");
    return false;
  }
  Texture* texture = texture_ref->texture();
  GLenum current_type = 0;
  GLenum internal_format = 0;
  if (!texture->GetLevelType(target, level, &current_type, &internal_format)) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_OPERATION, function_name, "level does not exist.");
    return false;
  }
  if (!texture_manager()->ValidateTextureParameters(state_.GetErrorState(),
      function_name, format, type, internal_format, level)) {
    return false;
  }
  if (type != current_type) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_OPERATION,
        function_name, "type does not match type of texture.");
    return false;
  }
  if (async_pixel_transfer_manager_->AsyncTransferIsInProgress(texture_ref)) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_OPERATION,
        function_name, "async upload pending for texture");
    return false;
  }
  if (!texture->ValidForTexture(
          target, level, xoffset, yoffset, width, height, type)) {
    LOCAL_SET_GL_ERROR(GL_INVALID_VALUE, function_name, "bad dimensions.");
    return false;
  }
  if ((GLES2Util::GetChannelsForFormat(format) &
       (GLES2Util::kDepth | GLES2Util::kStencil)) != 0) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_OPERATION,
        function_name, "can not supply data for depth or stencil textures");
    return false;
  }
  if (data == NULL) {
    (*error) = error::kOutOfBounds;
    return false;
  }
  return true;
}

error::Error GLES2DecoderImpl::DoTexSubImage2D(
    GLenum target,
    GLint level,
    GLint xoffset,
    GLint yoffset,
    GLsizei width,
    GLsizei height,
    GLenum format,
    GLenum type,
    const void * data) {
  error::Error error = error::kNoError;
  if (!ValidateTexSubImage2D(&error, "glTexSubImage2D", target, level,
      xoffset, yoffset, width, height, format, type, data)) {
    return error;
  }
  TextureRef* texture_ref = texture_manager()->GetTextureInfoForTarget(
      &state_, target);
  Texture* texture = texture_ref->texture();
  GLsizei tex_width = 0;
  GLsizei tex_height = 0;
  bool ok = texture->GetLevelSize(target, level, &tex_width, &tex_height);
  DCHECK(ok);
  if (xoffset != 0 || yoffset != 0 ||
      width != tex_width || height != tex_height) {
    if (!texture_manager()->ClearTextureLevel(this, texture_ref,
                                              target, level)) {
      LOCAL_SET_GL_ERROR(
          GL_OUT_OF_MEMORY, "glTexSubImage2D", "dimensions too big");
      return error::kNoError;
    }
    ScopedTextureUploadTimer timer(&texture_state_);
    glTexSubImage2D(
        target, level, xoffset, yoffset, width, height, format, type, data);
    return error::kNoError;
  }

  if (!texture_state_.texsubimage2d_faster_than_teximage2d &&
      !texture->IsImmutable()) {
    ScopedTextureUploadTimer timer(&texture_state_);
    GLenum internal_format;
    GLenum tex_type;
    texture->GetLevelType(target, level, &tex_type, &internal_format);
    // NOTE: In OpenGL ES 2.0 border is always zero. If that changes we'll need
    // to look it up.
    glTexImage2D(
        target, level, internal_format, width, height, 0, format, type, data);
  } else {
    ScopedTextureUploadTimer timer(&texture_state_);
    glTexSubImage2D(
        target, level, xoffset, yoffset, width, height, format, type, data);
  }
  texture_manager()->SetLevelCleared(texture_ref, target, level, true);
  return error::kNoError;
}

error::Error GLES2DecoderImpl::HandleTexSubImage2D(
    uint32 immediate_data_size, const cmds::TexSubImage2D& c) {
  TRACE_EVENT0("gpu", "GLES2DecoderImpl::HandleTexSubImage2D");
  GLboolean internal = static_cast<GLboolean>(c.internal);
  if (internal == GL_TRUE && texture_state_.tex_image_2d_failed)
    return error::kNoError;

  GLenum target = static_cast<GLenum>(c.target);
  GLint level = static_cast<GLint>(c.level);
  GLint xoffset = static_cast<GLint>(c.xoffset);
  GLint yoffset = static_cast<GLint>(c.yoffset);
  GLsizei width = static_cast<GLsizei>(c.width);
  GLsizei height = static_cast<GLsizei>(c.height);
  GLenum format = static_cast<GLenum>(c.format);
  GLenum type = static_cast<GLenum>(c.type);
  uint32 data_size;
  if (!GLES2Util::ComputeImageDataSizes(
      width, height, format, type, state_.unpack_alignment, &data_size,
      NULL, NULL)) {
    return error::kOutOfBounds;
  }
  const void* pixels = GetSharedMemoryAs<const void*>(
      c.pixels_shm_id, c.pixels_shm_offset, data_size);
  return DoTexSubImage2D(
      target, level, xoffset, yoffset, width, height, format, type, pixels);
}

error::Error GLES2DecoderImpl::HandleGetVertexAttribPointerv(
    uint32 immediate_data_size, const cmds::GetVertexAttribPointerv& c) {
  GLuint index = static_cast<GLuint>(c.index);
  GLenum pname = static_cast<GLenum>(c.pname);
  typedef cmds::GetVertexAttribPointerv::Result Result;
  Result* result = GetSharedMemoryAs<Result*>(
        c.pointer_shm_id, c.pointer_shm_offset, Result::ComputeSize(1));
  if (!result) {
    return error::kOutOfBounds;
  }
  // Check that the client initialized the result.
  if (result->size != 0) {
    return error::kInvalidArguments;
  }
  if (!validators_->vertex_pointer.IsValid(pname)) {
    LOCAL_SET_GL_ERROR_INVALID_ENUM(
        "glGetVertexAttribPointerv", pname, "pname");
    return error::kNoError;
  }
  if (index >= group_->max_vertex_attribs()) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_VALUE, "glGetVertexAttribPointerv", "index out of range.");
    return error::kNoError;
  }
  result->SetNumResults(1);
  *result->GetData() =
      state_.vertex_attrib_manager->GetVertexAttrib(index)->offset();
  return error::kNoError;
}

bool GLES2DecoderImpl::GetUniformSetup(
    GLuint program_id, GLint fake_location,
    uint32 shm_id, uint32 shm_offset,
    error::Error* error, GLint* real_location,
    GLuint* service_id, void** result_pointer, GLenum* result_type) {
  DCHECK(error);
  DCHECK(service_id);
  DCHECK(result_pointer);
  DCHECK(result_type);
  DCHECK(real_location);
  *error = error::kNoError;
  // Make sure we have enough room for the result on failure.
  SizedResult<GLint>* result;
  result = GetSharedMemoryAs<SizedResult<GLint>*>(
      shm_id, shm_offset, SizedResult<GLint>::ComputeSize(0));
  if (!result) {
    *error = error::kOutOfBounds;
    return false;
  }
  *result_pointer = result;
  // Set the result size to 0 so the client does not have to check for success.
  result->SetNumResults(0);
  Program* program = GetProgramInfoNotShader(program_id, "glGetUniform");
  if (!program) {
    return false;
  }
  if (!program->IsValid()) {
    // Program was not linked successfully. (ie, glLinkProgram)
    LOCAL_SET_GL_ERROR(
        GL_INVALID_OPERATION, "glGetUniform", "program not linked");
    return false;
  }
  *service_id = program->service_id();
  GLint array_index = -1;
  const Program::UniformInfo* uniform_info =
      program->GetUniformInfoByFakeLocation(
          fake_location, real_location, &array_index);
  if (!uniform_info) {
    // No such location.
    LOCAL_SET_GL_ERROR(
        GL_INVALID_OPERATION, "glGetUniform", "unknown location");
    return false;
  }
  GLenum type = uniform_info->type;
  GLsizei size = GLES2Util::GetGLDataTypeSizeForUniforms(type);
  if (size == 0) {
    LOCAL_SET_GL_ERROR(GL_INVALID_OPERATION, "glGetUniform", "unknown type");
    return false;
  }
  result = GetSharedMemoryAs<SizedResult<GLint>*>(
      shm_id, shm_offset, SizedResult<GLint>::ComputeSizeFromBytes(size));
  if (!result) {
    *error = error::kOutOfBounds;
    return false;
  }
  result->size = size;
  *result_type = type;
  return true;
}

error::Error GLES2DecoderImpl::HandleGetUniformiv(
    uint32 immediate_data_size, const cmds::GetUniformiv& c) {
  GLuint program = c.program;
  GLint fake_location = c.location;
  GLuint service_id;
  GLenum result_type;
  GLint real_location = -1;
  Error error;
  void* result;
  if (GetUniformSetup(
      program, fake_location, c.params_shm_id, c.params_shm_offset,
      &error, &real_location, &service_id, &result, &result_type)) {
    glGetUniformiv(
        service_id, real_location,
        static_cast<cmds::GetUniformiv::Result*>(result)->GetData());
  }
  return error;
}

error::Error GLES2DecoderImpl::HandleGetUniformfv(
    uint32 immediate_data_size, const cmds::GetUniformfv& c) {
  GLuint program = c.program;
  GLint fake_location = c.location;
  GLuint service_id;
  GLint real_location = -1;
  Error error;
  typedef cmds::GetUniformfv::Result Result;
  Result* result;
  GLenum result_type;
  if (GetUniformSetup(
      program, fake_location, c.params_shm_id, c.params_shm_offset,
      &error, &real_location, &service_id,
      reinterpret_cast<void**>(&result), &result_type)) {
    if (result_type == GL_BOOL || result_type == GL_BOOL_VEC2 ||
        result_type == GL_BOOL_VEC3 || result_type == GL_BOOL_VEC4) {
      GLsizei num_values = result->GetNumResults();
      scoped_ptr<GLint[]> temp(new GLint[num_values]);
      glGetUniformiv(service_id, real_location, temp.get());
      GLfloat* dst = result->GetData();
      for (GLsizei ii = 0; ii < num_values; ++ii) {
        dst[ii] = (temp[ii] != 0);
      }
    } else {
      glGetUniformfv(service_id, real_location, result->GetData());
    }
  }
  return error;
}

error::Error GLES2DecoderImpl::HandleGetShaderPrecisionFormat(
    uint32 immediate_data_size, const cmds::GetShaderPrecisionFormat& c) {
  GLenum shader_type = static_cast<GLenum>(c.shadertype);
  GLenum precision_type = static_cast<GLenum>(c.precisiontype);
  typedef cmds::GetShaderPrecisionFormat::Result Result;
  Result* result = GetSharedMemoryAs<Result*>(
      c.result_shm_id, c.result_shm_offset, sizeof(*result));
  if (!result) {
    return error::kOutOfBounds;
  }
  // Check that the client initialized the result.
  if (result->success != 0) {
    return error::kInvalidArguments;
  }
  if (!validators_->shader_type.IsValid(shader_type)) {
    LOCAL_SET_GL_ERROR_INVALID_ENUM(
        "glGetShaderPrecisionFormat", shader_type, "shader_type");
    return error::kNoError;
  }
  if (!validators_->shader_precision.IsValid(precision_type)) {
    LOCAL_SET_GL_ERROR_INVALID_ENUM(
        "glGetShaderPrecisionFormat", precision_type, "precision_type");
    return error::kNoError;
  }

  result->success = 1;  // true

  GLint range[2] = { 0, 0 };
  GLint precision = 0;
  GetShaderPrecisionFormatImpl(shader_type, precision_type, range, &precision);

  result->min_range = range[0];
  result->max_range = range[1];
  result->precision = precision;

  return error::kNoError;
}

error::Error GLES2DecoderImpl::HandleGetAttachedShaders(
    uint32 immediate_data_size, const cmds::GetAttachedShaders& c) {
  uint32 result_size = c.result_size;
  GLuint program_id = static_cast<GLuint>(c.program);
  Program* program = GetProgramInfoNotShader(
      program_id, "glGetAttachedShaders");
  if (!program) {
    return error::kNoError;
  }
  typedef cmds::GetAttachedShaders::Result Result;
  uint32 max_count = Result::ComputeMaxResults(result_size);
  Result* result = GetSharedMemoryAs<Result*>(
      c.result_shm_id, c.result_shm_offset, Result::ComputeSize(max_count));
  if (!result) {
    return error::kOutOfBounds;
  }
  // Check that the client initialized the result.
  if (result->size != 0) {
    return error::kInvalidArguments;
  }
  GLsizei count = 0;
  glGetAttachedShaders(
      program->service_id(), max_count, &count, result->GetData());
  for (GLsizei ii = 0; ii < count; ++ii) {
    if (!shader_manager()->GetClientId(result->GetData()[ii],
                                       &result->GetData()[ii])) {
      NOTREACHED();
      return error::kGenericError;
    }
  }
  result->SetNumResults(count);
  return error::kNoError;
}

error::Error GLES2DecoderImpl::HandleGetActiveUniform(
    uint32 immediate_data_size, const cmds::GetActiveUniform& c) {
  GLuint program_id = c.program;
  GLuint index = c.index;
  uint32 name_bucket_id = c.name_bucket_id;
  typedef cmds::GetActiveUniform::Result Result;
  Result* result = GetSharedMemoryAs<Result*>(
      c.result_shm_id, c.result_shm_offset, sizeof(*result));
  if (!result) {
    return error::kOutOfBounds;
  }
  // Check that the client initialized the result.
  if (result->success != 0) {
    return error::kInvalidArguments;
  }
  Program* program = GetProgramInfoNotShader(
      program_id, "glGetActiveUniform");
  if (!program) {
    return error::kNoError;
  }
  const Program::UniformInfo* uniform_info =
      program->GetUniformInfo(index);
  if (!uniform_info) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_VALUE, "glGetActiveUniform", "index out of range");
    return error::kNoError;
  }
  result->success = 1;  // true.
  result->size = uniform_info->size;
  result->type = uniform_info->type;
  Bucket* bucket = CreateBucket(name_bucket_id);
  bucket->SetFromString(uniform_info->name.c_str());
  return error::kNoError;
}

error::Error GLES2DecoderImpl::HandleGetActiveAttrib(
    uint32 immediate_data_size, const cmds::GetActiveAttrib& c) {
  GLuint program_id = c.program;
  GLuint index = c.index;
  uint32 name_bucket_id = c.name_bucket_id;
  typedef cmds::GetActiveAttrib::Result Result;
  Result* result = GetSharedMemoryAs<Result*>(
      c.result_shm_id, c.result_shm_offset, sizeof(*result));
  if (!result) {
    return error::kOutOfBounds;
  }
  // Check that the client initialized the result.
  if (result->success != 0) {
    return error::kInvalidArguments;
  }
  Program* program = GetProgramInfoNotShader(
      program_id, "glGetActiveAttrib");
  if (!program) {
    return error::kNoError;
  }
  const Program::VertexAttrib* attrib_info =
      program->GetAttribInfo(index);
  if (!attrib_info) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_VALUE, "glGetActiveAttrib", "index out of range");
    return error::kNoError;
  }
  result->success = 1;  // true.
  result->size = attrib_info->size;
  result->type = attrib_info->type;
  Bucket* bucket = CreateBucket(name_bucket_id);
  bucket->SetFromString(attrib_info->name.c_str());
  return error::kNoError;
}

error::Error GLES2DecoderImpl::HandleShaderBinary(
    uint32 immediate_data_size, const cmds::ShaderBinary& c) {
#if 1  // No binary shader support.
  LOCAL_SET_GL_ERROR(GL_INVALID_OPERATION, "glShaderBinary", "not supported");
  return error::kNoError;
#else
  GLsizei n = static_cast<GLsizei>(c.n);
  if (n < 0) {
    LOCAL_SET_GL_ERROR(GL_INVALID_VALUE, "glShaderBinary", "n < 0");
    return error::kNoError;
  }
  GLsizei length = static_cast<GLsizei>(c.length);
  if (length < 0) {
    LOCAL_SET_GL_ERROR(GL_INVALID_VALUE, "glShaderBinary", "length < 0");
    return error::kNoError;
  }
  uint32 data_size;
  if (!SafeMultiplyUint32(n, sizeof(GLuint), &data_size)) {
    return error::kOutOfBounds;
  }
  const GLuint* shaders = GetSharedMemoryAs<const GLuint*>(
      c.shaders_shm_id, c.shaders_shm_offset, data_size);
  GLenum binaryformat = static_cast<GLenum>(c.binaryformat);
  const void* binary = GetSharedMemoryAs<const void*>(
      c.binary_shm_id, c.binary_shm_offset, length);
  if (shaders == NULL || binary == NULL) {
    return error::kOutOfBounds;
  }
  scoped_array<GLuint> service_ids(new GLuint[n]);
  for (GLsizei ii = 0; ii < n; ++ii) {
    Shader* shader = GetShader(shaders[ii]);
    if (!shader) {
      LOCAL_SET_GL_ERROR(GL_INVALID_VALUE, "glShaderBinary", "unknown shader");
      return error::kNoError;
    }
    service_ids[ii] = shader->service_id();
  }
  // TODO(gman): call glShaderBinary
  return error::kNoError;
#endif
}

void GLES2DecoderImpl::DoSwapBuffers() {
  bool is_offscreen = !!offscreen_target_frame_buffer_.get();

  int this_frame_number = frame_number_++;
  // TRACE_EVENT for gpu tests:
  TRACE_EVENT_INSTANT2("test_gpu", "SwapBuffersLatency",
                       TRACE_EVENT_SCOPE_THREAD,
                       "GLImpl", static_cast<int>(gfx::GetGLImplementation()),
                       "width", (is_offscreen ? offscreen_size_.width() :
                                 surface_->GetSize().width()));
  TRACE_EVENT2("gpu", "GLES2DecoderImpl::DoSwapBuffers",
               "offscreen", is_offscreen,
               "frame", this_frame_number);
  {
    TRACE_EVENT_SYNTHETIC_DELAY("gpu.SwapBuffers");
  }

  bool is_tracing;
  TRACE_EVENT_CATEGORY_GROUP_ENABLED(TRACE_DISABLED_BY_DEFAULT("gpu.debug"),
                                     &is_tracing);
  if (is_tracing) {
    ScopedFrameBufferBinder binder(this, GetBackbufferServiceId());
    gpu_state_tracer_->TakeSnapshotWithCurrentFramebuffer(
        is_offscreen ? offscreen_size_ : surface_->GetSize());
  }

  // If offscreen then don't actually SwapBuffers to the display. Just copy
  // the rendered frame to another frame buffer.
  if (is_offscreen) {
    TRACE_EVENT2("gpu", "Offscreen",
        "width", offscreen_size_.width(), "height", offscreen_size_.height());
    if (offscreen_size_ != offscreen_saved_color_texture_->size()) {
      // Workaround for NVIDIA driver bug on OS X; crbug.com/89557,
      // crbug.com/94163. TODO(kbr): figure out reproduction so Apple will
      // fix this.
      if (workarounds().needs_offscreen_buffer_workaround) {
        offscreen_saved_frame_buffer_->Create();
        glFinish();
      }

      // Allocate the offscreen saved color texture.
      DCHECK(offscreen_saved_color_format_);
      offscreen_saved_color_texture_->AllocateStorage(
          offscreen_size_, offscreen_saved_color_format_, false);

      offscreen_saved_frame_buffer_->AttachRenderTexture(
          offscreen_saved_color_texture_.get());
      if (offscreen_size_.width() != 0 && offscreen_size_.height() != 0) {
        if (offscreen_saved_frame_buffer_->CheckStatus() !=
            GL_FRAMEBUFFER_COMPLETE) {
          LOG(ERROR) << "GLES2DecoderImpl::ResizeOffscreenFrameBuffer failed "
                     << "because offscreen saved FBO was incomplete.";
          LoseContext(GL_UNKNOWN_CONTEXT_RESET_ARB);
          return;
        }

        // Clear the offscreen color texture.
        // TODO(piman): Is this still necessary?
        {
          ScopedFrameBufferBinder binder(this,
                                         offscreen_saved_frame_buffer_->id());
          glClearColor(0, 0, 0, 0);
          glColorMask(GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE);
          glDisable(GL_SCISSOR_TEST);
          glClear(GL_COLOR_BUFFER_BIT);
          RestoreClearState();
        }
      }

      UpdateParentTextureInfo();
    }

    if (offscreen_size_.width() == 0 || offscreen_size_.height() == 0)
      return;
    ScopedGLErrorSuppressor suppressor(
        "GLES2DecoderImpl::DoSwapBuffers", GetErrorState());

    if (IsOffscreenBufferMultisampled()) {
      // For multisampled buffers, resolve the frame buffer.
      ScopedResolvedFrameBufferBinder binder(this, true, false);
    } else {
      ScopedFrameBufferBinder binder(this,
                                     offscreen_target_frame_buffer_->id());

      if (offscreen_target_buffer_preserved_) {
        // Copy the target frame buffer to the saved offscreen texture.
        offscreen_saved_color_texture_->Copy(
            offscreen_saved_color_texture_->size(),
            offscreen_saved_color_format_);
      } else {
        // Flip the textures in the parent context via the texture manager.
        if (!!offscreen_saved_color_texture_info_.get())
          offscreen_saved_color_texture_info_->texture()->
              SetServiceId(offscreen_target_color_texture_->id());

        offscreen_saved_color_texture_.swap(offscreen_target_color_texture_);
        offscreen_target_frame_buffer_->AttachRenderTexture(
            offscreen_target_color_texture_.get());
      }

      // Ensure the side effects of the copy are visible to the parent
      // context. There is no need to do this for ANGLE because it uses a
      // single D3D device for all contexts.
      if (!feature_info_->feature_flags().is_angle)
        glFlush();
    }
  } else {
    if (!surface_->SwapBuffers()) {
      LOG(ERROR) << "Context lost because SwapBuffers failed.";
      LoseContext(GL_UNKNOWN_CONTEXT_RESET_ARB);
    }
  }
}

error::Error GLES2DecoderImpl::HandleEnableFeatureCHROMIUM(
    uint32 immediate_data_size, const cmds::EnableFeatureCHROMIUM& c) {
  Bucket* bucket = GetBucket(c.bucket_id);
  if (!bucket || bucket->size() == 0) {
    return error::kInvalidArguments;
  }
  typedef cmds::EnableFeatureCHROMIUM::Result Result;
  Result* result = GetSharedMemoryAs<Result*>(
      c.result_shm_id, c.result_shm_offset, sizeof(*result));
  if (!result) {
    return error::kOutOfBounds;
  }
  // Check that the client initialized the result.
  if (*result != 0) {
    return error::kInvalidArguments;
  }
  std::string feature_str;
  if (!bucket->GetAsString(&feature_str)) {
    return error::kInvalidArguments;
  }

  // TODO(gman): make this some kind of table to function pointer thingy.
  if (feature_str.compare("pepper3d_allow_buffers_on_multiple_targets") == 0) {
    buffer_manager()->set_allow_buffers_on_multiple_targets(true);
  } else if (feature_str.compare("pepper3d_support_fixed_attribs") == 0) {
    buffer_manager()->set_allow_buffers_on_multiple_targets(true);
    // TODO(gman): decide how to remove the need for this const_cast.
    // I could make validators_ non const but that seems bad as this is the only
    // place it is needed. I could make some special friend class of validators
    // just to allow this to set them. That seems silly. I could refactor this
    // code to use the extension mechanism or the initialization attributes to
    // turn this feature on. Given that the only real point of this is to make
    // the conformance tests pass and given that there is lots of real work that
    // needs to be done it seems like refactoring for one to one of those
    // methods is a very low priority.
    const_cast<Validators*>(validators_)->vertex_attrib_type.AddValue(GL_FIXED);
  } else if (feature_str.compare("webgl_enable_glsl_webgl_validation") == 0) {
    force_webgl_glsl_validation_ = true;
    InitializeShaderTranslator();
  } else {
    return error::kNoError;
  }

  *result = 1;  // true.
  return error::kNoError;
}

error::Error GLES2DecoderImpl::HandleGetRequestableExtensionsCHROMIUM(
    uint32 immediate_data_size,
    const cmds::GetRequestableExtensionsCHROMIUM& c) {
  Bucket* bucket = CreateBucket(c.bucket_id);
  scoped_refptr<FeatureInfo> info(new FeatureInfo());
  info->Initialize(disallowed_features_);
  bucket->SetFromString(info->extensions().c_str());
  return error::kNoError;
}

error::Error GLES2DecoderImpl::HandleRequestExtensionCHROMIUM(
    uint32 immediate_data_size, const cmds::RequestExtensionCHROMIUM& c) {
  Bucket* bucket = GetBucket(c.bucket_id);
  if (!bucket || bucket->size() == 0) {
    return error::kInvalidArguments;
  }
  std::string feature_str;
  if (!bucket->GetAsString(&feature_str)) {
    return error::kInvalidArguments;
  }

  bool desire_webgl_glsl_validation =
      feature_str.find("GL_CHROMIUM_webglsl") != std::string::npos;
  bool desire_standard_derivatives = false;
  bool desire_frag_depth = false;
  bool desire_draw_buffers = false;
  if (force_webgl_glsl_validation_) {
    desire_standard_derivatives =
        feature_str.find("GL_OES_standard_derivatives") != std::string::npos;
    desire_frag_depth =
        feature_str.find("GL_EXT_frag_depth") != std::string::npos;
    desire_draw_buffers =
        feature_str.find("GL_EXT_draw_buffers") != std::string::npos;
  }

  if (desire_webgl_glsl_validation != force_webgl_glsl_validation_ ||
      desire_standard_derivatives != derivatives_explicitly_enabled_ ||
      desire_frag_depth != frag_depth_explicitly_enabled_ ||
      desire_draw_buffers != draw_buffers_explicitly_enabled_) {
    force_webgl_glsl_validation_ |= desire_webgl_glsl_validation;
    derivatives_explicitly_enabled_ |= desire_standard_derivatives;
    frag_depth_explicitly_enabled_ |= desire_frag_depth;
    draw_buffers_explicitly_enabled_ |= desire_draw_buffers;
    InitializeShaderTranslator();
  }

  UpdateCapabilities();

  return error::kNoError;
}

error::Error GLES2DecoderImpl::HandleGetMultipleIntegervCHROMIUM(
    uint32 immediate_data_size, const cmds::GetMultipleIntegervCHROMIUM& c) {
  GLuint count = c.count;
  uint32 pnames_size;
  if (!SafeMultiplyUint32(count, sizeof(GLenum), &pnames_size)) {
    return error::kOutOfBounds;
  }
  const GLenum* pnames = GetSharedMemoryAs<const GLenum*>(
      c.pnames_shm_id, c.pnames_shm_offset, pnames_size);
  if (pnames == NULL) {
    return error::kOutOfBounds;
  }

  // We have to copy them since we use them twice so the client
  // can't change them between the time we validate them and the time we use
  // them.
  scoped_ptr<GLenum[]> enums(new GLenum[count]);
  memcpy(enums.get(), pnames, pnames_size);

  // Count up the space needed for the result.
  uint32 num_results = 0;
  for (GLuint ii = 0; ii < count; ++ii) {
    uint32 num = util_.GLGetNumValuesReturned(enums[ii]);
    if (num == 0) {
      LOCAL_SET_GL_ERROR_INVALID_ENUM(
          "glGetMultipleCHROMIUM", enums[ii], "pname");
      return error::kNoError;
    }
    // Num will never be more than 4.
    DCHECK_LE(num, 4u);
    if (!SafeAddUint32(num_results, num, &num_results)) {
      return error::kOutOfBounds;
    }
  }

  uint32 result_size = 0;
  if (!SafeMultiplyUint32(num_results, sizeof(GLint), &result_size)) {
    return error::kOutOfBounds;
  }

  if (result_size != static_cast<uint32>(c.size)) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_VALUE,
        "glGetMultipleCHROMIUM", "bad size GL_INVALID_VALUE");
    return error::kNoError;
  }

  GLint* results = GetSharedMemoryAs<GLint*>(
      c.results_shm_id, c.results_shm_offset, result_size);
  if (results == NULL) {
    return error::kOutOfBounds;
  }

  // Check the results have been cleared in case the context was lost.
  for (uint32 ii = 0; ii < num_results; ++ii) {
    if (results[ii]) {
      return error::kInvalidArguments;
    }
  }

  // Get each result.
  GLint* start = results;
  for (GLuint ii = 0; ii < count; ++ii) {
    GLsizei num_written = 0;
    if (!state_.GetStateAsGLint(enums[ii], results, &num_written) &&
        !GetHelper(enums[ii], results, &num_written)) {
      DoGetIntegerv(enums[ii], results);
    }
    results += num_written;
  }

  // Just to verify. Should this be a DCHECK?
  if (static_cast<uint32>(results - start) != num_results) {
    return error::kOutOfBounds;
  }

  return error::kNoError;
}

error::Error GLES2DecoderImpl::HandleGetProgramInfoCHROMIUM(
    uint32 immediate_data_size, const cmds::GetProgramInfoCHROMIUM& c) {
  GLuint program_id = static_cast<GLuint>(c.program);
  uint32 bucket_id = c.bucket_id;
  Bucket* bucket = CreateBucket(bucket_id);
  bucket->SetSize(sizeof(ProgramInfoHeader));  // in case we fail.
  Program* program = NULL;
  program = GetProgram(program_id);
  if (!program || !program->IsValid()) {
    return error::kNoError;
  }
  program->GetProgramInfo(program_manager(), bucket);
  return error::kNoError;
}

error::ContextLostReason GLES2DecoderImpl::GetContextLostReason() {
  switch (reset_status_) {
    case GL_NO_ERROR:
      // TODO(kbr): improve the precision of the error code in this case.
      // Consider delegating to context for error code if MakeCurrent fails.
      return error::kUnknown;
    case GL_GUILTY_CONTEXT_RESET_ARB:
      return error::kGuilty;
    case GL_INNOCENT_CONTEXT_RESET_ARB:
      return error::kInnocent;
    case GL_UNKNOWN_CONTEXT_RESET_ARB:
      return error::kUnknown;
  }

  NOTREACHED();
  return error::kUnknown;
}

bool GLES2DecoderImpl::WasContextLost() {
  if (reset_status_ != GL_NO_ERROR) {
    return true;
  }
  if (context_->WasAllocatedUsingRobustnessExtension()) {
    GLenum status = GL_NO_ERROR;
    if (has_robustness_extension_)
      status = glGetGraphicsResetStatusARB();
    if (status != GL_NO_ERROR) {
      // The graphics card was reset. Signal a lost context to the application.
      reset_status_ = status;
      reset_by_robustness_extension_ = true;
      LOG(ERROR) << (surface_->IsOffscreen() ? "Offscreen" : "Onscreen")
                 << " context lost via ARB/EXT_robustness. Reset status = "
                 << GLES2Util::GetStringEnum(status);
      return true;
    }
  }
  return false;
}

bool GLES2DecoderImpl::WasContextLostByRobustnessExtension() {
  return WasContextLost() && reset_by_robustness_extension_;
}

void GLES2DecoderImpl::LoseContext(uint32 reset_status) {
  // Only loses the context once.
  if (reset_status_ != GL_NO_ERROR) {
    return;
  }

  // Marks this context as lost.
  reset_status_ = reset_status;
  current_decoder_error_ = error::kLostContext;
}

error::Error GLES2DecoderImpl::HandleLoseContextCHROMIUM(
    uint32 immediate_data_size, const cmds::LoseContextCHROMIUM& c) {
  GLenum current = static_cast<GLenum>(c.current);
  GLenum other = static_cast<GLenum>(c.other);
  if (!validators_->reset_status.IsValid(current)) {
    LOCAL_SET_GL_ERROR_INVALID_ENUM(
        "glLoseContextCHROMIUM", current, "current");
  }
  if (!validators_->reset_status.IsValid(other)) {
    LOCAL_SET_GL_ERROR_INVALID_ENUM("glLoseContextCHROMIUM", other, "other");
  }
  group_->LoseContexts(other);
  reset_status_ = current;
  current_decoder_error_ = error::kLostContext;
  return error::kLostContext;
}

error::Error GLES2DecoderImpl::HandleInsertSyncPointCHROMIUM(
    uint32 immediate_data_size, const cmds::InsertSyncPointCHROMIUM& c) {
  return error::kUnknownCommand;
}

error::Error GLES2DecoderImpl::HandleWaitSyncPointCHROMIUM(
    uint32 immediate_data_size, const cmds::WaitSyncPointCHROMIUM& c) {
  group_->mailbox_manager()->PullTextureUpdates();
  if (wait_sync_point_callback_.is_null())
    return error::kNoError;

  return wait_sync_point_callback_.Run(c.sync_point) ?
      error::kNoError : error::kDeferCommandUntilLater;
}

error::Error GLES2DecoderImpl::HandleDiscardBackbufferCHROMIUM(
    uint32 immediate_data_size, const cmds::DiscardBackbufferCHROMIUM& c) {
  if (surface_->DeferDraws())
    return error::kDeferCommandUntilLater;
  if (!surface_->SetBackbufferAllocation(false))
    return error::kLostContext;
  backbuffer_needs_clear_bits_ |= GL_COLOR_BUFFER_BIT;
  backbuffer_needs_clear_bits_ |= GL_DEPTH_BUFFER_BIT;
  backbuffer_needs_clear_bits_ |= GL_STENCIL_BUFFER_BIT;
  return error::kNoError;
}

bool GLES2DecoderImpl::GenQueriesEXTHelper(
    GLsizei n, const GLuint* client_ids) {
  for (GLsizei ii = 0; ii < n; ++ii) {
    if (query_manager_->GetQuery(client_ids[ii])) {
      return false;
    }
  }
  // NOTE: We don't generate Query objects here. Only in BeginQueryEXT
  return true;
}

void GLES2DecoderImpl::DeleteQueriesEXTHelper(
    GLsizei n, const GLuint* client_ids) {
  for (GLsizei ii = 0; ii < n; ++ii) {
    QueryManager::Query* query = query_manager_->GetQuery(client_ids[ii]);
    if (query && !query->IsDeleted()) {
      ContextState::QueryMap::iterator it =
          state_.current_queries.find(query->target());
      if (it != state_.current_queries.end())
        state_.current_queries.erase(it);

      query->Destroy(true);
      query_manager_->RemoveQuery(client_ids[ii]);
    }
  }
}

bool GLES2DecoderImpl::ProcessPendingQueries() {
  if (query_manager_.get() == NULL) {
    return false;
  }
  if (!query_manager_->ProcessPendingQueries()) {
    current_decoder_error_ = error::kOutOfBounds;
  }
  return query_manager_->HavePendingQueries();
}

// Note that if there are no pending readpixels right now,
// this function will call the callback immediately.
void GLES2DecoderImpl::WaitForReadPixels(base::Closure callback) {
  if (features().use_async_readpixels && !pending_readpixel_fences_.empty()) {
    pending_readpixel_fences_.back()->callbacks.push_back(callback);
  } else {
    callback.Run();
  }
}

void GLES2DecoderImpl::ProcessPendingReadPixels() {
  while (!pending_readpixel_fences_.empty() &&
         pending_readpixel_fences_.front()->fence->HasCompleted()) {
    std::vector<base::Closure> callbacks =
        pending_readpixel_fences_.front()->callbacks;
    pending_readpixel_fences_.pop();
    for (size_t i = 0; i < callbacks.size(); i++) {
      callbacks[i].Run();
    }
  }
}

bool GLES2DecoderImpl::HasMoreIdleWork() {
  return !pending_readpixel_fences_.empty() ||
      async_pixel_transfer_manager_->NeedsProcessMorePendingTransfers();
}

void GLES2DecoderImpl::PerformIdleWork() {
  ProcessPendingReadPixels();
  if (!async_pixel_transfer_manager_->NeedsProcessMorePendingTransfers())
    return;
  async_pixel_transfer_manager_->ProcessMorePendingTransfers();
  ProcessFinishedAsyncTransfers();
}

error::Error GLES2DecoderImpl::HandleBeginQueryEXT(
    uint32 immediate_data_size, const cmds::BeginQueryEXT& c) {
  GLenum target = static_cast<GLenum>(c.target);
  GLuint client_id = static_cast<GLuint>(c.id);
  int32 sync_shm_id = static_cast<int32>(c.sync_data_shm_id);
  uint32 sync_shm_offset = static_cast<uint32>(c.sync_data_shm_offset);

  switch (target) {
    case GL_COMMANDS_ISSUED_CHROMIUM:
    case GL_LATENCY_QUERY_CHROMIUM:
    case GL_ASYNC_PIXEL_UNPACK_COMPLETED_CHROMIUM:
    case GL_ASYNC_PIXEL_PACK_COMPLETED_CHROMIUM:
    case GL_GET_ERROR_QUERY_CHROMIUM:
      break;
    default:
      if (!features().occlusion_query_boolean) {
        LOCAL_SET_GL_ERROR(
            GL_INVALID_OPERATION, "glBeginQueryEXT",
            "not enabled for occlusion queries");
        return error::kNoError;
      }
      break;
  }

  if (state_.current_queries.find(target) != state_.current_queries.end()) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_OPERATION, "glBeginQueryEXT", "query already in progress");
    return error::kNoError;
  }

  if (client_id == 0) {
    LOCAL_SET_GL_ERROR(GL_INVALID_OPERATION, "glBeginQueryEXT", "id is 0");
    return error::kNoError;
  }

  QueryManager::Query* query = query_manager_->GetQuery(client_id);
  if (!query) {
    // TODO(gman): Decide if we need this check.
    //
    // Checks id was made by glGenQueries
    //
    // From the POV of OpenGL ES 2.0 you need to call glGenQueriesEXT
    // for all Query ids but from the POV of the command buffer service maybe
    // you don't.
    //
    // The client can enforce this. I don't think the service cares.
    //
    // IdAllocatorInterface* id_allocator =
    //     group_->GetIdAllocator(id_namespaces::kQueries);
    // if (!id_allocator->InUse(client_id)) {
    //   LOCAL_SET_GL_ERROR(
    //       GL_INVALID_OPERATION,
    //       "glBeginQueryEXT", "id not made by glGenQueriesEXT");
    //   return error::kNoError;
    // }
    query = query_manager_->CreateQuery(
        target, client_id, sync_shm_id, sync_shm_offset);
  }

  if (query->target() != target) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_OPERATION, "glBeginQueryEXT", "target does not match");
    return error::kNoError;
  } else if (query->shm_id() != sync_shm_id ||
             query->shm_offset() != sync_shm_offset) {
    DLOG(ERROR) << "Shared memory used by query not the same as before";
    return error::kInvalidArguments;
  }

  if (!query_manager_->BeginQuery(query)) {
    return error::kOutOfBounds;
  }

  state_.current_queries[target] = query;
  return error::kNoError;
}

error::Error GLES2DecoderImpl::HandleEndQueryEXT(
    uint32 immediate_data_size, const cmds::EndQueryEXT& c) {
  GLenum target = static_cast<GLenum>(c.target);
  uint32 submit_count = static_cast<GLuint>(c.submit_count);
  ContextState::QueryMap::iterator it = state_.current_queries.find(target);

  if (it == state_.current_queries.end()) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_OPERATION, "glEndQueryEXT", "No active query");
    return error::kNoError;
  }

  QueryManager::Query* query = it->second.get();
  if (!query_manager_->EndQuery(query, submit_count)) {
    return error::kOutOfBounds;
  }

  query_manager_->ProcessPendingTransferQueries();

  state_.current_queries.erase(it);
  return error::kNoError;
}

bool GLES2DecoderImpl::GenVertexArraysOESHelper(
    GLsizei n, const GLuint* client_ids) {
  for (GLsizei ii = 0; ii < n; ++ii) {
    if (GetVertexAttribManager(client_ids[ii])) {
      return false;
    }
  }

  if (!features().native_vertex_array_object) {
    // Emulated VAO
    for (GLsizei ii = 0; ii < n; ++ii) {
      CreateVertexAttribManager(client_ids[ii], 0);
    }
  } else {
    scoped_ptr<GLuint[]> service_ids(new GLuint[n]);

    glGenVertexArraysOES(n, service_ids.get());
    for (GLsizei ii = 0; ii < n; ++ii) {
      CreateVertexAttribManager(client_ids[ii], service_ids[ii]);
    }
  }

  return true;
}

void GLES2DecoderImpl::DeleteVertexArraysOESHelper(
    GLsizei n, const GLuint* client_ids) {
  for (GLsizei ii = 0; ii < n; ++ii) {
    VertexAttribManager* vao =
        GetVertexAttribManager(client_ids[ii]);
    if (vao && !vao->IsDeleted()) {
      if (state_.vertex_attrib_manager.get() == vao) {
        state_.vertex_attrib_manager = default_vertex_attrib_manager_;
      }
      RemoveVertexAttribManager(client_ids[ii]);
    }
  }
}

void GLES2DecoderImpl::DoBindVertexArrayOES(GLuint client_id) {
  VertexAttribManager* vao = NULL;
  GLuint service_id = 0;
  if (client_id != 0) {
    vao = GetVertexAttribManager(client_id);
    if (!vao) {
      // Unlike most Bind* methods, the spec explicitly states that VertexArray
      // only allows names that have been previously generated. As such, we do
      // not generate new names here.
      LOCAL_SET_GL_ERROR(
          GL_INVALID_OPERATION,
          "glBindVertexArrayOES", "bad vertex array id.");
      current_decoder_error_ = error::kNoError;
      return;
    } else {
      service_id = vao->service_id();
    }
  } else {
    vao = default_vertex_attrib_manager_.get();
  }

  // Only set the VAO state if it's changed
  if (state_.vertex_attrib_manager.get() != vao) {
    state_.vertex_attrib_manager = vao;
    if (!features().native_vertex_array_object) {
      EmulateVertexArrayState();
    } else {
      glBindVertexArrayOES(service_id);
    }
  }
}

// Used when OES_vertex_array_object isn't natively supported
void GLES2DecoderImpl::EmulateVertexArrayState() {
  // Setup the Vertex attribute state
  for (uint32 vv = 0; vv < group_->max_vertex_attribs(); ++vv) {
    RestoreStateForAttrib(vv);
  }

  // Setup the element buffer
  Buffer* element_array_buffer =
      state_.vertex_attrib_manager->element_array_buffer();
  glBindBuffer(GL_ELEMENT_ARRAY_BUFFER,
      element_array_buffer ? element_array_buffer->service_id() : 0);
}

bool GLES2DecoderImpl::DoIsVertexArrayOES(GLuint client_id) {
  const VertexAttribManager* vao =
      GetVertexAttribManager(client_id);
  return vao && vao->IsValid() && !vao->IsDeleted();
}

#if defined(OS_MACOSX)
void GLES2DecoderImpl::ReleaseIOSurfaceForTexture(GLuint texture_id) {
  TextureToIOSurfaceMap::iterator it = texture_to_io_surface_map_.find(
      texture_id);
  if (it != texture_to_io_surface_map_.end()) {
    // Found a previous IOSurface bound to this texture; release it.
    CFTypeRef surface = it->second;
    CFRelease(surface);
    texture_to_io_surface_map_.erase(it);
  }
}
#endif

void GLES2DecoderImpl::DoTexImageIOSurface2DCHROMIUM(
    GLenum target, GLsizei width, GLsizei height,
    GLuint io_surface_id, GLuint plane) {
#if defined(OS_MACOSX)
  if (gfx::GetGLImplementation() != gfx::kGLImplementationDesktopGL) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_OPERATION,
        "glTexImageIOSurface2DCHROMIUM", "only supported on desktop GL.");
    return;
  }

  IOSurfaceSupport* surface_support = IOSurfaceSupport::Initialize();
  if (!surface_support) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_OPERATION,
        "glTexImageIOSurface2DCHROMIUM", "only supported on 10.6.");
    return;
  }

  if (target != GL_TEXTURE_RECTANGLE_ARB) {
    // This might be supported in the future, and if we could require
    // support for binding an IOSurface to a NPOT TEXTURE_2D texture, we
    // could delete a lot of code. For now, perform strict validation so we
    // know what's going on.
    LOCAL_SET_GL_ERROR(
        GL_INVALID_OPERATION,
        "glTexImageIOSurface2DCHROMIUM",
        "requires TEXTURE_RECTANGLE_ARB target");
    return;
  }

  // Default target might be conceptually valid, but disallow it to avoid
  // accidents.
  TextureRef* texture_ref =
      texture_manager()->GetTextureInfoForTargetUnlessDefault(&state_, target);
  if (!texture_ref) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_OPERATION,
        "glTexImageIOSurface2DCHROMIUM", "no rectangle texture bound");
    return;
  }

  // Look up the new IOSurface. Note that because of asynchrony
  // between processes this might fail; during live resizing the
  // plugin process might allocate and release an IOSurface before
  // this process gets a chance to look it up. Hold on to any old
  // IOSurface in this case.
  CFTypeRef surface = surface_support->IOSurfaceLookup(io_surface_id);
  if (!surface) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_OPERATION,
        "glTexImageIOSurface2DCHROMIUM", "no IOSurface with the given ID");
    return;
  }

  // Release any IOSurface previously bound to this texture.
  ReleaseIOSurfaceForTexture(texture_ref->service_id());

  // Make sure we release the IOSurface even if CGLTexImageIOSurface2D fails.
  texture_to_io_surface_map_.insert(
      std::make_pair(texture_ref->service_id(), surface));

  CGLContextObj context =
      static_cast<CGLContextObj>(context_->GetHandle());

  CGLError err = surface_support->CGLTexImageIOSurface2D(
      context,
      target,
      GL_RGBA,
      width,
      height,
      GL_BGRA,
      GL_UNSIGNED_INT_8_8_8_8_REV,
      surface,
      plane);

  if (err != kCGLNoError) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_OPERATION,
        "glTexImageIOSurface2DCHROMIUM", "error in CGLTexImageIOSurface2D");
    return;
  }

  texture_manager()->SetLevelInfo(
      texture_ref, target, 0, GL_RGBA, width, height, 1, 0,
      GL_BGRA, GL_UNSIGNED_INT_8_8_8_8_REV, true);

#else
  LOCAL_SET_GL_ERROR(GL_INVALID_OPERATION,
             "glTexImageIOSurface2DCHROMIUM", "not supported.");
#endif
}

static GLenum ExtractFormatFromStorageFormat(GLenum internalformat) {
  switch (internalformat) {
    case GL_RGB565:
      return GL_RGB;
    case GL_RGBA4:
      return GL_RGBA;
    case GL_RGB5_A1:
      return GL_RGBA;
    case GL_RGB8_OES:
      return GL_RGB;
    case GL_RGBA8_OES:
      return GL_RGBA;
    case GL_LUMINANCE8_ALPHA8_EXT:
      return GL_LUMINANCE_ALPHA;
    case GL_LUMINANCE8_EXT:
      return GL_LUMINANCE;
    case GL_ALPHA8_EXT:
      return GL_ALPHA;
    case GL_RGBA32F_EXT:
      return GL_RGBA;
    case GL_RGB32F_EXT:
      return GL_RGB;
    case GL_ALPHA32F_EXT:
      return GL_ALPHA;
    case GL_LUMINANCE32F_EXT:
      return GL_LUMINANCE;
    case GL_LUMINANCE_ALPHA32F_EXT:
      return GL_LUMINANCE_ALPHA;
    case GL_RGBA16F_EXT:
      return GL_RGBA;
    case GL_RGB16F_EXT:
      return GL_RGB;
    case GL_ALPHA16F_EXT:
      return GL_ALPHA;
    case GL_LUMINANCE16F_EXT:
      return GL_LUMINANCE;
    case GL_LUMINANCE_ALPHA16F_EXT:
      return GL_LUMINANCE_ALPHA;
    case GL_BGRA8_EXT:
      return GL_BGRA_EXT;
    default:
      return GL_NONE;
  }
}

void GLES2DecoderImpl::DoCopyTextureCHROMIUM(
    GLenum target, GLuint source_id, GLuint dest_id, GLint level,
    GLenum internal_format, GLenum dest_type) {
  TextureRef* dest_texture_ref = GetTexture(dest_id);
  TextureRef* source_texture_ref = GetTexture(source_id);

  if (!source_texture_ref || !dest_texture_ref) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_VALUE, "glCopyTextureCHROMIUM", "unknown texture id");
    return;
  }

  if (GL_TEXTURE_2D != target) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_VALUE, "glCopyTextureCHROMIUM", "invalid texture target");
    return;
  }

  Texture* source_texture = source_texture_ref->texture();
  Texture* dest_texture = dest_texture_ref->texture();
  if (dest_texture->target() != GL_TEXTURE_2D ||
      (source_texture->target() != GL_TEXTURE_2D &&
      source_texture->target() != GL_TEXTURE_EXTERNAL_OES)) {
    LOCAL_SET_GL_ERROR(GL_INVALID_VALUE,
                       "glCopyTextureCHROMIUM",
                       "invalid texture target binding");
    return;
  }

  int source_width, source_height, dest_width, dest_height;

  gfx::GLImage* image =
      source_texture->GetLevelImage(source_texture->target(), 0);
  if (image) {
    gfx::Size size = image->GetSize();
    source_width = size.width();
    source_height = size.height();
    if (source_width <= 0 || source_height <= 0) {
      LOCAL_SET_GL_ERROR(
          GL_INVALID_VALUE,
          "glCopyTextureChromium", "invalid image size");
      return;
    }
  } else {
    if (!source_texture->GetLevelSize(
             source_texture->target(), 0, &source_width, &source_height)) {
      LOCAL_SET_GL_ERROR(GL_INVALID_VALUE,
                         "glCopyTextureChromium",
                         "source texture has no level 0");
      return;
    }

    // Check that this type of texture is allowed.
    if (!texture_manager()->ValidForTarget(
             source_texture->target(), level, source_width, source_height, 1)) {
      LOCAL_SET_GL_ERROR(
          GL_INVALID_VALUE, "glCopyTextureCHROMIUM", "Bad dimensions");
      return;
    }
  }

  // Clear the source texture if necessary.
  if (!texture_manager()->ClearTextureLevel(
          this, source_texture_ref, source_texture->target(), 0)) {
    LOCAL_SET_GL_ERROR(
        GL_OUT_OF_MEMORY, "glCopyTextureCHROMIUM", "dimensions too big");
    return;
  }

  // Defer initializing the CopyTextureCHROMIUMResourceManager until it is
  // needed because it takes 10s of milliseconds to initialize.
  if (!copy_texture_CHROMIUM_.get()) {
    LOCAL_COPY_REAL_GL_ERRORS_TO_WRAPPER("glCopyTextureCHROMIUM");
    copy_texture_CHROMIUM_.reset(new CopyTextureCHROMIUMResourceManager());
    copy_texture_CHROMIUM_->Initialize(this);
    RestoreCurrentFramebufferBindings();
    if (LOCAL_PEEK_GL_ERROR("glCopyTextureCHROMIUM") != GL_NO_ERROR)
      return;
  }

  GLenum dest_type_previous;
  GLenum dest_internal_format;
  bool dest_level_defined = dest_texture->GetLevelSize(
      GL_TEXTURE_2D, level, &dest_width, &dest_height);

  if (dest_level_defined) {
    dest_texture->GetLevelType(GL_TEXTURE_2D, level, &dest_type_previous,
                               &dest_internal_format);
  }

  // Resize the destination texture to the dimensions of the source texture.
  if (!dest_level_defined || dest_width != source_width ||
      dest_height != source_height ||
      dest_internal_format != internal_format ||
      dest_type_previous != dest_type) {
    // Ensure that the glTexImage2D succeeds.
    LOCAL_COPY_REAL_GL_ERRORS_TO_WRAPPER("glCopyTextureCHROMIUM");
    glBindTexture(GL_TEXTURE_2D, dest_texture->service_id());
    glTexImage2D(
        GL_TEXTURE_2D, level, internal_format, source_width, source_height,
        0, internal_format, dest_type, NULL);
    GLenum error = LOCAL_PEEK_GL_ERROR("glCopyTextureCHROMIUM");
    if (error != GL_NO_ERROR) {
      RestoreCurrentTextureBindings(&state_, GL_TEXTURE_2D);
      return;
    }

    texture_manager()->SetLevelInfo(
        dest_texture_ref, GL_TEXTURE_2D, level, internal_format, source_width,
        source_height, 1, 0, internal_format, dest_type, true);
  } else {
    texture_manager()->SetLevelCleared(
        dest_texture_ref, GL_TEXTURE_2D, level, true);
  }

  DoWillUseTexImageIfNeeded(source_texture, source_texture->target());
  ScopedModifyPixels modify(dest_texture_ref);

  // GL_TEXTURE_EXTERNAL_OES texture requires apply a transform matrix
  // before presenting.
  if (source_texture->target() == GL_TEXTURE_EXTERNAL_OES) {
    // TODO(hkuang): get the StreamTexture transform matrix in GPU process
    // instead of using default matrix crbug.com/226218.
    const static GLfloat default_matrix[16] = {1.0f, 0.0f, 0.0f, 0.0f,
                                               0.0f, 1.0f, 0.0f, 0.0f,
                                               0.0f, 0.0f, 1.0f, 0.0f,
                                               0.0f, 0.0f, 0.0f, 1.0f};
    copy_texture_CHROMIUM_->DoCopyTextureWithTransform(
        this,
        source_texture->target(),
        dest_texture->target(),
        source_texture->service_id(),
        dest_texture->service_id(), level,
        source_width, source_height,
        unpack_flip_y_,
        unpack_premultiply_alpha_,
        unpack_unpremultiply_alpha_,
        default_matrix);
  } else {
    copy_texture_CHROMIUM_->DoCopyTexture(
        this,
        source_texture->target(),
        dest_texture->target(),
        source_texture->service_id(),
        dest_texture->service_id(), level,
        source_width, source_height,
        unpack_flip_y_,
        unpack_premultiply_alpha_,
        unpack_unpremultiply_alpha_);
  }

  DoDidUseTexImageIfNeeded(source_texture, source_texture->target());
}

static GLenum ExtractTypeFromStorageFormat(GLenum internalformat) {
  switch (internalformat) {
    case GL_RGB565:
      return GL_UNSIGNED_SHORT_5_6_5;
    case GL_RGBA4:
      return GL_UNSIGNED_SHORT_4_4_4_4;
    case GL_RGB5_A1:
      return GL_UNSIGNED_SHORT_5_5_5_1;
    case GL_RGB8_OES:
      return GL_UNSIGNED_BYTE;
    case GL_RGBA8_OES:
      return GL_UNSIGNED_BYTE;
    case GL_LUMINANCE8_ALPHA8_EXT:
      return GL_UNSIGNED_BYTE;
    case GL_LUMINANCE8_EXT:
      return GL_UNSIGNED_BYTE;
    case GL_ALPHA8_EXT:
      return GL_UNSIGNED_BYTE;
    case GL_RGBA32F_EXT:
      return GL_FLOAT;
    case GL_RGB32F_EXT:
      return GL_FLOAT;
    case GL_ALPHA32F_EXT:
      return GL_FLOAT;
    case GL_LUMINANCE32F_EXT:
      return GL_FLOAT;
    case GL_LUMINANCE_ALPHA32F_EXT:
      return GL_FLOAT;
    case GL_RGBA16F_EXT:
      return GL_HALF_FLOAT_OES;
    case GL_RGB16F_EXT:
      return GL_HALF_FLOAT_OES;
    case GL_ALPHA16F_EXT:
      return GL_HALF_FLOAT_OES;
    case GL_LUMINANCE16F_EXT:
      return GL_HALF_FLOAT_OES;
    case GL_LUMINANCE_ALPHA16F_EXT:
      return GL_HALF_FLOAT_OES;
    case GL_BGRA8_EXT:
      return GL_UNSIGNED_BYTE;
    default:
      return GL_NONE;
  }
}

void GLES2DecoderImpl::DoTexStorage2DEXT(
    GLenum target,
    GLint levels,
    GLenum internal_format,
    GLsizei width,
    GLsizei height) {
  TRACE_EVENT0("gpu", "GLES2DecoderImpl::DoTexStorage2DEXT");
  if (!texture_manager()->ValidForTarget(target, 0, width, height, 1) ||
      TextureManager::ComputeMipMapCount(target, width, height, 1) < levels) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_VALUE, "glTexStorage2DEXT", "dimensions out of range");
    return;
  }
  TextureRef* texture_ref = texture_manager()->GetTextureInfoForTarget(
      &state_, target);
  if (!texture_ref) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_OPERATION,
        "glTexStorage2DEXT", "unknown texture for target");
    return;
  }
  Texture* texture = texture_ref->texture();
  if (texture->IsAttachedToFramebuffer()) {
    framebuffer_state_.clear_state_dirty = true;
  }
  if (texture->IsImmutable()) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_OPERATION,
        "glTexStorage2DEXT", "texture is immutable");
    return;
  }

  GLenum format = ExtractFormatFromStorageFormat(internal_format);
  GLenum type = ExtractTypeFromStorageFormat(internal_format);

  {
    GLsizei level_width = width;
    GLsizei level_height = height;
    uint32 estimated_size = 0;
    for (int ii = 0; ii < levels; ++ii) {
      uint32 level_size = 0;
      if (!GLES2Util::ComputeImageDataSizes(
          level_width, level_height, format, type, state_.unpack_alignment,
          &estimated_size, NULL, NULL) ||
          !SafeAddUint32(estimated_size, level_size, &estimated_size)) {
        LOCAL_SET_GL_ERROR(
            GL_OUT_OF_MEMORY, "glTexStorage2DEXT", "dimensions too large");
        return;
      }
      level_width = std::max(1, level_width >> 1);
      level_height = std::max(1, level_height >> 1);
    }
    if (!EnsureGPUMemoryAvailable(estimated_size)) {
      LOCAL_SET_GL_ERROR(
          GL_OUT_OF_MEMORY, "glTexStorage2DEXT", "out of memory");
      return;
    }
  }

  LOCAL_COPY_REAL_GL_ERRORS_TO_WRAPPER("glTexStorage2DEXT");
  glTexStorage2DEXT(target, levels, internal_format, width, height);
  GLenum error = LOCAL_PEEK_GL_ERROR("glTexStorage2DEXT");
  if (error == GL_NO_ERROR) {
    GLsizei level_width = width;
    GLsizei level_height = height;
    for (int ii = 0; ii < levels; ++ii) {
      texture_manager()->SetLevelInfo(
          texture_ref, target, ii, format,
          level_width, level_height, 1, 0, format, type, false);
      level_width = std::max(1, level_width >> 1);
      level_height = std::max(1, level_height >> 1);
    }
    texture->SetImmutable(true);
  }
}

error::Error GLES2DecoderImpl::HandleGenMailboxCHROMIUM(
    uint32 immediate_data_size, const cmds::GenMailboxCHROMIUM& c) {
  return error::kUnknownCommand;
}

void GLES2DecoderImpl::DoProduceTextureCHROMIUM(GLenum target,
                                                const GLbyte* data) {
  TRACE_EVENT2("gpu", "GLES2DecoderImpl::DoProduceTextureCHROMIUM",
      "context", logger_.GetLogPrefix(),
      "mailbox[0]", static_cast<unsigned char>(data[0]));

  const Mailbox& mailbox = *reinterpret_cast<const Mailbox*>(data);
  DLOG_IF(ERROR, !mailbox.Verify()) << "ProduceTextureCHROMIUM was passed a "
                                       "mailbox that was not generated by "
                                       "GenMailboxCHROMIUM.";

  TextureRef* texture_ref = texture_manager()->GetTextureInfoForTarget(
      &state_, target);
  if (!texture_ref) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_OPERATION,
        "glProduceTextureCHROMIUM", "unknown texture for target");
    return;
  }

  Texture* produced = texture_manager()->Produce(texture_ref);
  if (!produced) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_OPERATION,
        "glProduceTextureCHROMIUM", "invalid texture");
    return;
  }

  group_->mailbox_manager()->ProduceTexture(target, mailbox, produced);
}

void GLES2DecoderImpl::DoConsumeTextureCHROMIUM(GLenum target,
                                                const GLbyte* data) {
  TRACE_EVENT2("gpu", "GLES2DecoderImpl::DoConsumeTextureCHROMIUM",
      "context", logger_.GetLogPrefix(),
      "mailbox[0]", static_cast<unsigned char>(data[0]));
  const Mailbox& mailbox = *reinterpret_cast<const Mailbox*>(data);
  DLOG_IF(ERROR, !mailbox.Verify()) << "ConsumeTextureCHROMIUM was passed a "
                                       "mailbox that was not generated by "
                                       "GenMailboxCHROMIUM.";

  scoped_refptr<TextureRef> texture_ref =
      texture_manager()->GetTextureInfoForTargetUnlessDefault(&state_, target);
  if (!texture_ref.get()) {
    LOCAL_SET_GL_ERROR(GL_INVALID_OPERATION,
                       "glConsumeTextureCHROMIUM",
                       "unknown texture for target");
    return;
  }
  GLuint client_id = texture_ref->client_id();
  if (!client_id) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_OPERATION,
        "glConsumeTextureCHROMIUM", "unknown texture for target");
    return;
  }
  Texture* texture = group_->mailbox_manager()->ConsumeTexture(target, mailbox);
  if (!texture) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_OPERATION,
        "glConsumeTextureCHROMIUM", "invalid mailbox name");
    return;
  }
  if (texture->target() != target) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_OPERATION,
        "glConsumeTextureCHROMIUM", "invalid target");
    return;
  }

  DeleteTexturesHelper(1, &client_id);
  texture_ref = texture_manager()->Consume(client_id, texture);
  glBindTexture(target, texture_ref->service_id());

  TextureUnit& unit = state_.texture_units[state_.active_texture_unit];
  unit.bind_target = target;
  switch (target) {
    case GL_TEXTURE_2D:
      unit.bound_texture_2d = texture_ref;
      break;
    case GL_TEXTURE_CUBE_MAP:
      unit.bound_texture_cube_map = texture_ref;
      break;
    case GL_TEXTURE_EXTERNAL_OES:
      unit.bound_texture_external_oes = texture_ref;
      break;
    case GL_TEXTURE_RECTANGLE_ARB:
      unit.bound_texture_rectangle_arb = texture_ref;
      break;
    default:
      NOTREACHED();  // Validation should prevent us getting here.
      break;
  }
}

void GLES2DecoderImpl::DoInsertEventMarkerEXT(
    GLsizei length, const GLchar* marker) {
  if (!marker) {
    marker = "";
  }
  debug_marker_manager_.SetMarker(
      length ? std::string(marker, length) : std::string(marker));
}

void GLES2DecoderImpl::DoPushGroupMarkerEXT(
    GLsizei length, const GLchar* marker) {
  if (!marker) {
    marker = "";
  }
  std::string name = length ? std::string(marker, length) : std::string(marker);
  debug_marker_manager_.PushGroup(name);
  gpu_tracer_->Begin(name, kTraceGroupMarker);
}

void GLES2DecoderImpl::DoPopGroupMarkerEXT(void) {
  debug_marker_manager_.PopGroup();
  gpu_tracer_->End(kTraceGroupMarker);
}

void GLES2DecoderImpl::DoBindTexImage2DCHROMIUM(
    GLenum target, GLint image_id) {
  TRACE_EVENT0("gpu", "GLES2DecoderImpl::DoBindTexImage2DCHROMIUM");

  if (target == GL_TEXTURE_CUBE_MAP) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_ENUM,
        "glBindTexImage2DCHROMIUM", "invalid target");
    return;
  }

  // Default target might be conceptually valid, but disallow it to avoid
  // accidents.
  TextureRef* texture_ref =
      texture_manager()->GetTextureInfoForTargetUnlessDefault(&state_, target);
  if (!texture_ref) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_OPERATION,
        "glBindTexImage2DCHROMIUM", "no texture bound");
    return;
  }

  gfx::GLImage* gl_image = image_manager()->LookupImage(image_id);
  if (!gl_image) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_OPERATION,
        "glBindTexImage2DCHROMIUM", "no image found with the given ID");
    return;
  }

  {
    ScopedGLErrorSuppressor suppressor(
        "GLES2DecoderImpl::DoBindTexImage2DCHROMIUM", GetErrorState());
    if (!gl_image->BindTexImage(target)) {
      LOCAL_SET_GL_ERROR(
          GL_INVALID_OPERATION,
          "glBindTexImage2DCHROMIUM", "fail to bind image with the given ID");
      return;
    }
  }

  gfx::Size size = gl_image->GetSize();
  texture_manager()->SetLevelInfo(
      texture_ref, target, 0, GL_RGBA, size.width(), size.height(), 1, 0,
      GL_RGBA, GL_UNSIGNED_BYTE, true);
  texture_manager()->SetLevelImage(texture_ref, target, 0, gl_image);
}

void GLES2DecoderImpl::DoReleaseTexImage2DCHROMIUM(
    GLenum target, GLint image_id) {
  TRACE_EVENT0("gpu", "GLES2DecoderImpl::DoReleaseTexImage2DCHROMIUM");

  // Default target might be conceptually valid, but disallow it to avoid
  // accidents.
  TextureRef* texture_ref =
      texture_manager()->GetTextureInfoForTargetUnlessDefault(&state_, target);
  if (!texture_ref) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_OPERATION,
        "glReleaseTexImage2DCHROMIUM", "no texture bound");
    return;
  }

  gfx::GLImage* gl_image = image_manager()->LookupImage(image_id);
  if (!gl_image) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_OPERATION,
        "glReleaseTexImage2DCHROMIUM", "no image found with the given ID");
    return;
  }

  // Do nothing when image is not currently bound.
  if (texture_ref->texture()->GetLevelImage(target, 0) != gl_image)
    return;

  {
    ScopedGLErrorSuppressor suppressor(
        "GLES2DecoderImpl::DoReleaseTexImage2DCHROMIUM", GetErrorState());
    gl_image->ReleaseTexImage(target);
  }

  texture_manager()->SetLevelInfo(
      texture_ref, target, 0, GL_RGBA, 0, 0, 1, 0,
      GL_RGBA, GL_UNSIGNED_BYTE, false);
}

error::Error GLES2DecoderImpl::HandleTraceBeginCHROMIUM(
    uint32 immediate_data_size, const cmds::TraceBeginCHROMIUM& c) {
  Bucket* bucket = GetBucket(c.bucket_id);
  if (!bucket || bucket->size() == 0) {
    return error::kInvalidArguments;
  }
  std::string command_name;
  if (!bucket->GetAsString(&command_name)) {
    return error::kInvalidArguments;
  }
  TRACE_EVENT_COPY_ASYNC_BEGIN0("gpu", command_name.c_str(), this);
  if (!gpu_tracer_->Begin(command_name, kTraceCHROMIUM)) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_OPERATION,
        "glTraceBeginCHROMIUM", "unable to create begin trace");
    return error::kNoError;
  }
  return error::kNoError;
}

void GLES2DecoderImpl::DoTraceEndCHROMIUM() {
  if (gpu_tracer_->CurrentName().empty()) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_OPERATION,
        "glTraceEndCHROMIUM", "no trace begin found");
    return;
  }
  TRACE_EVENT_COPY_ASYNC_END0("gpu", gpu_tracer_->CurrentName().c_str(), this);
  gpu_tracer_->End(kTraceCHROMIUM);
}

void GLES2DecoderImpl::DoDrawBuffersEXT(
    GLsizei count, const GLenum* bufs) {
  if (count > static_cast<GLsizei>(group_->max_draw_buffers())) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_VALUE,
        "glDrawBuffersEXT", "greater than GL_MAX_DRAW_BUFFERS_EXT");
    return;
  }

  Framebuffer* framebuffer = GetFramebufferInfoForTarget(GL_FRAMEBUFFER);
  if (framebuffer) {
    for (GLsizei i = 0; i < count; ++i) {
      if (bufs[i] != static_cast<GLenum>(GL_COLOR_ATTACHMENT0 + i) &&
          bufs[i] != GL_NONE) {
        LOCAL_SET_GL_ERROR(
            GL_INVALID_OPERATION,
            "glDrawBuffersEXT",
            "bufs[i] not GL_NONE or GL_COLOR_ATTACHMENTi_EXT");
        return;
      }
    }
    glDrawBuffersARB(count, bufs);
    framebuffer->SetDrawBuffers(count, bufs);
  } else {  // backbuffer
    if (count > 1 ||
        (bufs[0] != GL_BACK && bufs[0] != GL_NONE)) {
      LOCAL_SET_GL_ERROR(
          GL_INVALID_OPERATION,
          "glDrawBuffersEXT",
          "more than one buffer or bufs not GL_NONE or GL_BACK");
      return;
    }
    GLenum mapped_buf = bufs[0];
    if (GetBackbufferServiceId() != 0 &&  // emulated backbuffer
        bufs[0] == GL_BACK) {
      mapped_buf = GL_COLOR_ATTACHMENT0;
    }
    glDrawBuffersARB(count, &mapped_buf);
    group_->set_draw_buffer(bufs[0]);
  }
}

bool GLES2DecoderImpl::ValidateAsyncTransfer(
    const char* function_name,
    TextureRef* texture_ref,
    GLenum target,
    GLint level,
    const void * data) {
  // We only support async uploads to 2D textures for now.
  if (GL_TEXTURE_2D != target) {
    LOCAL_SET_GL_ERROR_INVALID_ENUM(function_name, target, "target");
    return false;
  }
  // We only support uploads to level zero for now.
  if (level != 0) {
    LOCAL_SET_GL_ERROR(GL_INVALID_VALUE, function_name, "level != 0");
    return false;
  }
  // A transfer buffer must be bound, even for asyncTexImage2D.
  if (data == NULL) {
    LOCAL_SET_GL_ERROR(GL_INVALID_OPERATION, function_name, "buffer == 0");
    return false;
  }
  // We only support one async transfer in progress.
  if (!texture_ref ||
      async_pixel_transfer_manager_->AsyncTransferIsInProgress(texture_ref)) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_OPERATION,
        function_name, "transfer already in progress");
    return false;
  }
  return true;
}

base::Closure GLES2DecoderImpl::AsyncUploadTokenCompletionClosure(
    uint32 async_upload_token,
    uint32 sync_data_shm_id,
    uint32 sync_data_shm_offset) {
  scoped_refptr<gpu::Buffer> buffer = GetSharedMemoryBuffer(sync_data_shm_id);
  if (!buffer || !buffer->GetDataAddress(sync_data_shm_offset,
                                         sizeof(AsyncUploadSync)))
    return base::Closure();

  AsyncMemoryParams mem_params(buffer,
                               sync_data_shm_offset,
                               sizeof(AsyncUploadSync));

  scoped_refptr<AsyncUploadTokenCompletionObserver> observer(
      new AsyncUploadTokenCompletionObserver(async_upload_token));

  return base::Bind(
      &AsyncPixelTransferManager::AsyncNotifyCompletion,
      base::Unretained(GetAsyncPixelTransferManager()),
      mem_params,
      observer);
}

error::Error GLES2DecoderImpl::HandleAsyncTexImage2DCHROMIUM(
    uint32 immediate_data_size, const cmds::AsyncTexImage2DCHROMIUM& c) {
  TRACE_EVENT0("gpu", "GLES2DecoderImpl::HandleAsyncTexImage2DCHROMIUM");
  GLenum target = static_cast<GLenum>(c.target);
  GLint level = static_cast<GLint>(c.level);
  // TODO(kloveless): Change HandleAsyncTexImage2DCHROMIUM command to use
  // unsigned integer for internalformat.
  GLenum internal_format = static_cast<GLenum>(c.internalformat);
  GLsizei width = static_cast<GLsizei>(c.width);
  GLsizei height = static_cast<GLsizei>(c.height);
  GLint border = static_cast<GLint>(c.border);
  GLenum format = static_cast<GLenum>(c.format);
  GLenum type = static_cast<GLenum>(c.type);
  uint32 pixels_shm_id = static_cast<uint32>(c.pixels_shm_id);
  uint32 pixels_shm_offset = static_cast<uint32>(c.pixels_shm_offset);
  uint32 pixels_size;
  uint32 async_upload_token = static_cast<uint32>(c.async_upload_token);
  uint32 sync_data_shm_id = static_cast<uint32>(c.sync_data_shm_id);
  uint32 sync_data_shm_offset = static_cast<uint32>(c.sync_data_shm_offset);

  base::ScopedClosureRunner scoped_completion_callback;
  if (async_upload_token) {
    base::Closure completion_closure =
        AsyncUploadTokenCompletionClosure(async_upload_token,
                                          sync_data_shm_id,
                                          sync_data_shm_offset);
    if (completion_closure.is_null())
      return error::kInvalidArguments;

    scoped_completion_callback.Reset(completion_closure);
  }

  // TODO(epenner): Move this and copies of this memory validation
  // into ValidateTexImage2D step.
  if (!GLES2Util::ComputeImageDataSizes(
      width, height, format, type, state_.unpack_alignment, &pixels_size, NULL,
      NULL)) {
    return error::kOutOfBounds;
  }
  const void* pixels = NULL;
  if (pixels_shm_id != 0 || pixels_shm_offset != 0) {
    pixels = GetSharedMemoryAs<const void*>(
        pixels_shm_id, pixels_shm_offset, pixels_size);
    if (!pixels) {
      return error::kOutOfBounds;
    }
  }

  TextureManager::DoTextImage2DArguments args = {
    target, level, internal_format, width, height, border, format, type,
    pixels, pixels_size};
  TextureRef* texture_ref;
  // All the normal glTexSubImage2D validation.
  if (!texture_manager()->ValidateTexImage2D(
      &state_, "glAsyncTexImage2DCHROMIUM", args, &texture_ref)) {
    return error::kNoError;
  }

  // Extra async validation.
  Texture* texture = texture_ref->texture();
  if (!ValidateAsyncTransfer(
      "glAsyncTexImage2DCHROMIUM", texture_ref, target, level, pixels))
    return error::kNoError;

  // Don't allow async redefinition of a textures.
  if (texture->IsDefined()) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_OPERATION,
        "glAsyncTexImage2DCHROMIUM", "already defined");
    return error::kNoError;
  }

  if (!EnsureGPUMemoryAvailable(pixels_size)) {
    LOCAL_SET_GL_ERROR(
        GL_OUT_OF_MEMORY, "glAsyncTexImage2DCHROMIUM", "out of memory");
    return error::kNoError;
  }

  // Setup the parameters.
  AsyncTexImage2DParams tex_params = {
      target, level, static_cast<GLenum>(internal_format),
      width, height, border, format, type};
  AsyncMemoryParams mem_params(
      GetSharedMemoryBuffer(c.pixels_shm_id), c.pixels_shm_offset, pixels_size);

  // Set up the async state if needed, and make the texture
  // immutable so the async state stays valid. The level info
  // is set up lazily when the transfer completes.
  AsyncPixelTransferDelegate* delegate =
      async_pixel_transfer_manager_->CreatePixelTransferDelegate(texture_ref,
                                                                 tex_params);
  texture->SetImmutable(true);

  delegate->AsyncTexImage2D(
      tex_params,
      mem_params,
      base::Bind(&TextureManager::SetLevelInfoFromParams,
                 // The callback is only invoked if the transfer delegate still
                 // exists, which implies through manager->texture_ref->state
                 // ownership that both of these pointers are valid.
                 base::Unretained(texture_manager()),
                 base::Unretained(texture_ref),
                 tex_params));
  return error::kNoError;
}

error::Error GLES2DecoderImpl::HandleAsyncTexSubImage2DCHROMIUM(
    uint32 immediate_data_size, const cmds::AsyncTexSubImage2DCHROMIUM& c) {
  TRACE_EVENT0("gpu", "GLES2DecoderImpl::HandleAsyncTexSubImage2DCHROMIUM");
  GLenum target = static_cast<GLenum>(c.target);
  GLint level = static_cast<GLint>(c.level);
  GLint xoffset = static_cast<GLint>(c.xoffset);
  GLint yoffset = static_cast<GLint>(c.yoffset);
  GLsizei width = static_cast<GLsizei>(c.width);
  GLsizei height = static_cast<GLsizei>(c.height);
  GLenum format = static_cast<GLenum>(c.format);
  GLenum type = static_cast<GLenum>(c.type);
  uint32 async_upload_token = static_cast<uint32>(c.async_upload_token);
  uint32 sync_data_shm_id = static_cast<uint32>(c.sync_data_shm_id);
  uint32 sync_data_shm_offset = static_cast<uint32>(c.sync_data_shm_offset);

  base::ScopedClosureRunner scoped_completion_callback;
  if (async_upload_token) {
    base::Closure completion_closure =
        AsyncUploadTokenCompletionClosure(async_upload_token,
                                          sync_data_shm_id,
                                          sync_data_shm_offset);
    if (completion_closure.is_null())
      return error::kInvalidArguments;

    scoped_completion_callback.Reset(completion_closure);
  }

  // TODO(epenner): Move this and copies of this memory validation
  // into ValidateTexSubImage2D step.
  uint32 data_size;
  if (!GLES2Util::ComputeImageDataSizes(
      width, height, format, type, state_.unpack_alignment, &data_size,
      NULL, NULL)) {
    return error::kOutOfBounds;
  }
  const void* pixels = GetSharedMemoryAs<const void*>(
      c.data_shm_id, c.data_shm_offset, data_size);

  // All the normal glTexSubImage2D validation.
  error::Error error = error::kNoError;
  if (!ValidateTexSubImage2D(&error, "glAsyncTexSubImage2DCHROMIUM",
      target, level, xoffset, yoffset, width, height, format, type, pixels)) {
    return error;
  }

  // Extra async validation.
  TextureRef* texture_ref = texture_manager()->GetTextureInfoForTarget(
      &state_, target);
  Texture* texture = texture_ref->texture();
  if (!ValidateAsyncTransfer(
         "glAsyncTexSubImage2DCHROMIUM", texture_ref, target, level, pixels))
    return error::kNoError;

  // Guarantee async textures are always 'cleared' as follows:
  // - AsyncTexImage2D can not redefine an existing texture
  // - AsyncTexImage2D must initialize the entire image via non-null buffer.
  // - AsyncTexSubImage2D clears synchronously if not already cleared.
  // - Textures become immutable after an async call.
  // This way we know in all cases that an async texture is always clear.
  if (!texture->SafeToRenderFrom()) {
    if (!texture_manager()->ClearTextureLevel(this, texture_ref,
                                              target, level)) {
      LOCAL_SET_GL_ERROR(
          GL_OUT_OF_MEMORY,
          "glAsyncTexSubImage2DCHROMIUM", "dimensions too big");
      return error::kNoError;
    }
  }

  // Setup the parameters.
  AsyncTexSubImage2DParams tex_params = {target, level, xoffset, yoffset,
                                              width, height, format, type};
  AsyncMemoryParams mem_params(
      GetSharedMemoryBuffer(c.data_shm_id), c.data_shm_offset, data_size);
  AsyncPixelTransferDelegate* delegate =
      async_pixel_transfer_manager_->GetPixelTransferDelegate(texture_ref);
  if (!delegate) {
    // TODO(epenner): We may want to enforce exclusive use
    // of async APIs in which case this should become an error,
    // (the texture should have been async defined).
    AsyncTexImage2DParams define_params = {target, level,
                                                0, 0, 0, 0, 0, 0};
    texture->GetLevelSize(target, level, &define_params.width,
                                         &define_params.height);
    texture->GetLevelType(target, level, &define_params.type,
                                         &define_params.internal_format);
    // Set up the async state if needed, and make the texture
    // immutable so the async state stays valid.
    delegate = async_pixel_transfer_manager_->CreatePixelTransferDelegate(
        texture_ref, define_params);
    texture->SetImmutable(true);
  }

  delegate->AsyncTexSubImage2D(tex_params, mem_params);
  return error::kNoError;
}

error::Error GLES2DecoderImpl::HandleWaitAsyncTexImage2DCHROMIUM(
    uint32 immediate_data_size, const cmds::WaitAsyncTexImage2DCHROMIUM& c) {
  TRACE_EVENT0("gpu", "GLES2DecoderImpl::HandleWaitAsyncTexImage2DCHROMIUM");
  GLenum target = static_cast<GLenum>(c.target);

  if (GL_TEXTURE_2D != target) {
    LOCAL_SET_GL_ERROR(
        GL_INVALID_ENUM, "glWaitAsyncTexImage2DCHROMIUM", "target");
    return error::kNoError;
  }
  TextureRef* texture_ref = texture_manager()->GetTextureInfoForTarget(
      &state_, target);
  if (!texture_ref) {
      LOCAL_SET_GL_ERROR(
          GL_INVALID_OPERATION,
          "glWaitAsyncTexImage2DCHROMIUM", "unknown texture");
    return error::kNoError;
  }
  AsyncPixelTransferDelegate* delegate =
      async_pixel_transfer_manager_->GetPixelTransferDelegate(texture_ref);
  if (!delegate) {
      LOCAL_SET_GL_ERROR(
          GL_INVALID_OPERATION,
          "glWaitAsyncTexImage2DCHROMIUM", "No async transfer started");
    return error::kNoError;
  }
  delegate->WaitForTransferCompletion();
  ProcessFinishedAsyncTransfers();
  return error::kNoError;
}

error::Error GLES2DecoderImpl::HandleWaitAllAsyncTexImage2DCHROMIUM(
    uint32 immediate_data_size, const cmds::WaitAllAsyncTexImage2DCHROMIUM& c) {
  TRACE_EVENT0("gpu", "GLES2DecoderImpl::HandleWaitAsyncTexImage2DCHROMIUM");

  GetAsyncPixelTransferManager()->WaitAllAsyncTexImage2D();
  ProcessFinishedAsyncTransfers();
  return error::kNoError;
}

void GLES2DecoderImpl::OnTextureRefDetachedFromFramebuffer(
    TextureRef* texture_ref) {
  Texture* texture = texture_ref->texture();
  DoDidUseTexImageIfNeeded(texture, texture->target());
}

void GLES2DecoderImpl::OnOutOfMemoryError() {
  if (lose_context_when_out_of_memory_) {
    group_->LoseContexts(GL_UNKNOWN_CONTEXT_RESET_ARB);
    LoseContext(GL_GUILTY_CONTEXT_RESET_ARB);
  }
}

// Include the auto-generated part of this file. We split this because it means
// we can easily edit the non-auto generated parts right here in this file
// instead of having to edit some template or the code generator.
#include "gpu/command_buffer/service/gles2_cmd_decoder_autogen.h"

}  // namespace gles2
}  // namespace gpu
/* [<][>][^][v][top][bottom][index][help] */
root/gpu/command_buffer/service/gles2_cmd_decoder.cc

DEFINITIONS
