root/content/browser/loader/resource_dispatcher_host_impl.cc

DEFINITIONS

1. IsDetachableResourceType
2. AbortRequestBeforeItStarts
3. SetReferrerForRequest
4. ShouldServiceRequest
5. RemoveDownloadFileFromChildSecurityPolicy
6. CallbackAndReturn
7. GetCertID
8. NotifyRedirectOnUI
9. NotifyResponseOnUI
10. IsValidatedSCT
11. Get
12. allow_cross_origin_auth_prompt_
13. Get
14. SetDelegate
15. SetAllowCrossOriginAuthPrompt
16. AddResourceContext
17. RemoveResourceContext
18. CancelRequestsForContext
19. BeginDownload
20. ClearLoginDelegateForRequest
21. Shutdown
22. CreateResourceHandlerForDownload
23. MaybeInterceptAsStream
24. ClearSSLClientAuthHandlerForRequest
25. CreateLoginDelegate
26. HandleExternalProtocol
27. DidStartRequest
28. DidReceiveRedirect
29. DidReceiveResponse
30. DidFinishLoading
31. OnInit
32. OnShutdown
33. OnMessageReceived
34. OnRequestResource
35. OnSyncLoad
36. UpdateRequestForTransfer
37. BeginRequest
38. CreateResourceHandler
39. OnReleaseDownloadedFile
40. OnDataDownloadedACK
41. RegisterDownloadedTempFile
42. UnregisterDownloadedTempFile
43. Send
44. OnUploadProgressACK
45. OnCancelRequest
46. CreateRequestInfo
47. OnRenderViewHostCreated
48. OnRenderViewHostDeleted
49. BeginSaveFile
50. MarkAsTransferredNavigation
51. CancelTransferringNavigation
52. ResumeDeferredNavigation
53. CancelRequestsForProcess
54. CancelRequestsForRoute
55. RemovePendingRequest
56. RemovePendingLoader
57. CancelRequest
58. GetOutstandingRequestsStats
59. UpdateOutstandingRequestsStats
60. IncrementOutstandingRequestsMemory
61. IncrementOutstandingRequestsCount
62. HasSufficientResourcesForRequest
63. FinishedWithResourcesForRequest
64. CalculateApproximateMemoryCost
65. BeginRequestInternal
66. StartLoading
67. OnUserGesture
68. GetURLRequest
69. MoreInterestingLoadState
70. LoadInfoUpdateCallback
71. UpdateLoadStates
72. BlockRequestsForRoute
73. ResumeBlockedRequestsForRoute
74. CancelBlockedRequestsForRoute
75. ProcessBlockedRequestsForRoute
76. HttpAuthRelationTypeOf
77. allow_cross_origin_auth_prompt
78. IsTransferredNavigation
79. GetLoader
80. GetLoader
81. RegisterResourceMessageDelegate
82. UnregisterResourceMessageDelegate
83. BuildLoadFlagsForRequest

// 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.

// See http://dev.chromium.org/developers/design-documents/multi-process-resource-loading

#include "content/browser/loader/resource_dispatcher_host_impl.h"

#include <algorithm>
#include <set>
#include <vector>

#include "base/bind.h"
#include "base/bind_helpers.h"
#include "base/command_line.h"
#include "base/compiler_specific.h"
#include "base/debug/alias.h"
#include "base/logging.h"
#include "base/memory/scoped_ptr.h"
#include "base/memory/shared_memory.h"
#include "base/message_loop/message_loop.h"
#include "base/metrics/histogram.h"
#include "base/metrics/sparse_histogram.h"
#include "base/stl_util.h"
#include "base/third_party/dynamic_annotations/dynamic_annotations.h"
#include "content/browser/appcache/appcache_interceptor.h"
#include "content/browser/appcache/chrome_appcache_service.h"
#include "content/browser/cert_store_impl.h"
#include "content/browser/child_process_security_policy_impl.h"
#include "content/browser/cross_site_request_manager.h"
#include "content/browser/download/download_resource_handler.h"
#include "content/browser/download/save_file_manager.h"
#include "content/browser/download/save_file_resource_handler.h"
#include "content/browser/fileapi/chrome_blob_storage_context.h"
#include "content/browser/loader/async_resource_handler.h"
#include "content/browser/loader/buffered_resource_handler.h"
#include "content/browser/loader/cross_site_resource_handler.h"
#include "content/browser/loader/detachable_resource_handler.h"
#include "content/browser/loader/power_save_block_resource_throttle.h"
#include "content/browser/loader/redirect_to_file_resource_handler.h"
#include "content/browser/loader/resource_message_filter.h"
#include "content/browser/loader/resource_request_info_impl.h"
#include "content/browser/loader/stream_resource_handler.h"
#include "content/browser/loader/sync_resource_handler.h"
#include "content/browser/loader/throttling_resource_handler.h"
#include "content/browser/loader/upload_data_stream_builder.h"
#include "content/browser/plugin_service_impl.h"
#include "content/browser/renderer_host/render_view_host_delegate.h"
#include "content/browser/renderer_host/render_view_host_impl.h"
#include "content/browser/resource_context_impl.h"
#include "content/browser/service_worker/service_worker_request_handler.h"
#include "content/browser/streams/stream.h"
#include "content/browser/streams/stream_context.h"
#include "content/browser/streams/stream_registry.h"
#include "content/browser/worker_host/worker_service_impl.h"
#include "content/browser/web_contents/web_contents_impl.h"
#include "content/common/resource_messages.h"
#include "content/common/resource_request_body.h"
#include "content/common/ssl_status_serialization.h"
#include "content/common/view_messages.h"
#include "content/public/browser/browser_thread.h"
#include "content/public/browser/content_browser_client.h"
#include "content/public/browser/download_manager.h"
#include "content/public/browser/download_url_parameters.h"
#include "content/public/browser/global_request_id.h"
#include "content/public/browser/resource_dispatcher_host_delegate.h"
#include "content/public/browser/resource_request_details.h"
#include "content/public/browser/resource_throttle.h"
#include "content/public/browser/stream_handle.h"
#include "content/public/browser/user_metrics.h"
#include "content/public/common/content_switches.h"
#include "content/public/common/process_type.h"
#include "content/public/common/url_constants.h"
#include "ipc/ipc_message_macros.h"
#include "ipc/ipc_message_start.h"
#include "net/base/auth.h"
#include "net/base/load_flags.h"
#include "net/base/mime_util.h"
#include "net/base/net_errors.h"
#include "net/base/registry_controlled_domains/registry_controlled_domain.h"
#include "net/base/request_priority.h"
#include "net/base/upload_data_stream.h"
#include "net/cert/cert_status_flags.h"
#include "net/cookies/cookie_monster.h"
#include "net/http/http_response_headers.h"
#include "net/http/http_response_info.h"
#include "net/ssl/ssl_cert_request_info.h"
#include "net/url_request/url_request.h"
#include "net/url_request/url_request_context.h"
#include "net/url_request/url_request_job_factory.h"
#include "webkit/common/blob/blob_data.h"
#include "webkit/browser/blob/blob_data_handle.h"
#include "webkit/browser/blob/blob_storage_context.h"
#include "webkit/browser/blob/blob_url_request_job_factory.h"
#include "webkit/browser/fileapi/file_permission_policy.h"
#include "webkit/browser/fileapi/file_system_context.h"
#include "webkit/common/appcache/appcache_interfaces.h"
#include "webkit/common/blob/shareable_file_reference.h"

using base::Time;
using base::TimeDelta;
using base::TimeTicks;
using webkit_blob::ShareableFileReference;

// ----------------------------------------------------------------------------

namespace content {

namespace {

static ResourceDispatcherHostImpl* g_resource_dispatcher_host;

// The interval for calls to ResourceDispatcherHostImpl::UpdateLoadStates
const int kUpdateLoadStatesIntervalMsec = 100;

// Maximum byte "cost" of all the outstanding requests for a renderer.
// See delcaration of |max_outstanding_requests_cost_per_process_| for details.
// This bound is 25MB, which allows for around 6000 outstanding requests.
const int kMaxOutstandingRequestsCostPerProcess = 26214400;

// The number of milliseconds after noting a user gesture that we will
// tag newly-created URLRequest objects with the
// net::LOAD_MAYBE_USER_GESTURE load flag. This is a fairly arbitrary
// guess at how long to expect direct impact from a user gesture, but
// this should be OK as the load flag is a best-effort thing only,
// rather than being intended as fully accurate.
const int kUserGestureWindowMs = 3500;

// Ratio of |max_num_in_flight_requests_| that any one renderer is allowed to
// use. Arbitrarily chosen.
const double kMaxRequestsPerProcessRatio = 0.45;

// TODO(jkarlin): The value is high to reduce the chance of the detachable
// request timing out, forcing a blocked second request to open a new connection
// and start over. Reduce this value once we have a better idea of what it
// should be and once we stop blocking multiple simultaneous requests for the
// same resource (see bugs 46104 and 31014).
const int kDefaultDetachableCancelDelayMs = 30000;

bool IsDetachableResourceType(ResourceType::Type type) {
  switch (type) {
    case ResourceType::PREFETCH:
    case ResourceType::PING:
      return true;
    default:
      return false;
  }
}

// Aborts a request before an URLRequest has actually been created.
void AbortRequestBeforeItStarts(ResourceMessageFilter* filter,
                                IPC::Message* sync_result,
                                int request_id) {
  if (sync_result) {
    SyncLoadResult result;
    result.error_code = net::ERR_ABORTED;
    ResourceHostMsg_SyncLoad::WriteReplyParams(sync_result, result);
    filter->Send(sync_result);
  } else {
    // Tell the renderer that this request was disallowed.
    ResourceMsg_RequestCompleteData request_complete_data;
    request_complete_data.error_code = net::ERR_ABORTED;
    request_complete_data.was_ignored_by_handler = false;
    request_complete_data.exists_in_cache = false;
    // No security info needed, connection not established.
    request_complete_data.completion_time = base::TimeTicks();
    request_complete_data.encoded_data_length = 0;
    filter->Send(new ResourceMsg_RequestComplete(
        request_id, request_complete_data));
  }
}

void SetReferrerForRequest(net::URLRequest* request, const Referrer& referrer) {
  if (!referrer.url.is_valid() ||
      CommandLine::ForCurrentProcess()->HasSwitch(switches::kNoReferrers)) {
    request->SetReferrer(std::string());
  } else {
    request->SetReferrer(referrer.url.spec());
  }

  net::URLRequest::ReferrerPolicy net_referrer_policy =
      net::URLRequest::CLEAR_REFERRER_ON_TRANSITION_FROM_SECURE_TO_INSECURE;
  switch (referrer.policy) {
    case blink::WebReferrerPolicyDefault:
      net_referrer_policy =
          net::URLRequest::CLEAR_REFERRER_ON_TRANSITION_FROM_SECURE_TO_INSECURE;
      break;
    case blink::WebReferrerPolicyAlways:
    case blink::WebReferrerPolicyNever:
    case blink::WebReferrerPolicyOrigin:
      net_referrer_policy = net::URLRequest::NEVER_CLEAR_REFERRER;
      break;
  }
  request->set_referrer_policy(net_referrer_policy);
}

// Consults the RendererSecurity policy to determine whether the
// ResourceDispatcherHostImpl should service this request.  A request might be
// disallowed if the renderer is not authorized to retrieve the request URL or
// if the renderer is attempting to upload an unauthorized file.
bool ShouldServiceRequest(int process_type,
                          int child_id,
                          const ResourceHostMsg_Request& request_data,
                          fileapi::FileSystemContext* file_system_context)  {
  if (process_type == PROCESS_TYPE_PLUGIN)
    return true;

  ChildProcessSecurityPolicyImpl* policy =
      ChildProcessSecurityPolicyImpl::GetInstance();

  // Check if the renderer is permitted to request the requested URL.
  if (!policy->CanRequestURL(child_id, request_data.url)) {
    VLOG(1) << "Denied unauthorized request for "
            << request_data.url.possibly_invalid_spec();
    return false;
  }

  // Check if the renderer is permitted to upload the requested files.
  if (request_data.request_body.get()) {
    const std::vector<ResourceRequestBody::Element>* uploads =
        request_data.request_body->elements();
    std::vector<ResourceRequestBody::Element>::const_iterator iter;
    for (iter = uploads->begin(); iter != uploads->end(); ++iter) {
      if (iter->type() == ResourceRequestBody::Element::TYPE_FILE &&
          !policy->CanReadFile(child_id, iter->path())) {
        NOTREACHED() << "Denied unauthorized upload of "
                     << iter->path().value();
        return false;
      }
      if (iter->type() == ResourceRequestBody::Element::TYPE_FILE_FILESYSTEM) {
        fileapi::FileSystemURL url =
            file_system_context->CrackURL(iter->filesystem_url());
        if (!policy->CanReadFileSystemFile(child_id, url)) {
          NOTREACHED() << "Denied unauthorized upload of "
                       << iter->filesystem_url().spec();
          return false;
        }
      }
    }
  }

  return true;
}

void RemoveDownloadFileFromChildSecurityPolicy(int child_id,
                                               const base::FilePath& path) {
  ChildProcessSecurityPolicyImpl::GetInstance()->RevokeAllPermissionsForFile(
      child_id, path);
}

#if defined(OS_WIN)
#pragma warning(disable: 4748)
#pragma optimize("", off)
#endif

#if defined(OS_WIN)
#pragma optimize("", on)
#pragma warning(default: 4748)
#endif

DownloadInterruptReason CallbackAndReturn(
    const DownloadUrlParameters::OnStartedCallback& started_cb,
    DownloadInterruptReason interrupt_reason) {
  if (started_cb.is_null())
    return interrupt_reason;
  BrowserThread::PostTask(
      BrowserThread::UI,
      FROM_HERE,
      base::Bind(
          started_cb, static_cast<DownloadItem*>(NULL), interrupt_reason));

  return interrupt_reason;
}

int GetCertID(net::URLRequest* request, int child_id) {
  if (request->ssl_info().cert.get()) {
    return CertStore::GetInstance()->StoreCert(request->ssl_info().cert.get(),
                                               child_id);
  }
  return 0;
}

void NotifyRedirectOnUI(int render_process_id,
                        int render_frame_host,
                        scoped_ptr<ResourceRedirectDetails> details) {
  RenderFrameHostImpl* host =
      RenderFrameHostImpl::FromID(render_process_id, render_frame_host);
  WebContentsImpl* web_contents =
      static_cast<WebContentsImpl*>(WebContents::FromRenderFrameHost(host));
  if (!web_contents)
    return;
  web_contents->DidGetRedirectForResourceRequest(
      host->render_view_host(), *details.get());
}

void NotifyResponseOnUI(int render_process_id,
                        int render_frame_host,
                        scoped_ptr<ResourceRequestDetails> details) {
  RenderFrameHostImpl* host =
      RenderFrameHostImpl::FromID(render_process_id, render_frame_host);
  WebContentsImpl* web_contents =
      static_cast<WebContentsImpl*>(WebContents::FromRenderFrameHost(host));
  if (!web_contents)
    return;
  web_contents->DidGetResourceResponseStart(*details.get());
}

bool IsValidatedSCT(
    const net::SignedCertificateTimestampAndStatus& sct_status) {
  return sct_status.status == net::ct::SCT_STATUS_OK;
}

}  // namespace

// static
ResourceDispatcherHost* ResourceDispatcherHost::Get() {
  return g_resource_dispatcher_host;
}

ResourceDispatcherHostImpl::ResourceDispatcherHostImpl()
    : save_file_manager_(new SaveFileManager()),
      request_id_(-1),
      is_shutdown_(false),
      num_in_flight_requests_(0),
      max_num_in_flight_requests_(base::SharedMemory::GetHandleLimit()),
      max_num_in_flight_requests_per_process_(
          static_cast<int>(
              max_num_in_flight_requests_ * kMaxRequestsPerProcessRatio)),
      max_outstanding_requests_cost_per_process_(
          kMaxOutstandingRequestsCostPerProcess),
      filter_(NULL),
      delegate_(NULL),
      allow_cross_origin_auth_prompt_(false) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  DCHECK(!g_resource_dispatcher_host);
  g_resource_dispatcher_host = this;

  GetContentClient()->browser()->ResourceDispatcherHostCreated();

  ANNOTATE_BENIGN_RACE(
      &last_user_gesture_time_,
      "We don't care about the precise value, see http://crbug.com/92889");

  BrowserThread::PostTask(BrowserThread::IO,
                          FROM_HERE,
                          base::Bind(&ResourceDispatcherHostImpl::OnInit,
                                     base::Unretained(this)));

  update_load_states_timer_.reset(
      new base::RepeatingTimer<ResourceDispatcherHostImpl>());
}

ResourceDispatcherHostImpl::~ResourceDispatcherHostImpl() {
  DCHECK(outstanding_requests_stats_map_.empty());
  DCHECK(g_resource_dispatcher_host);
  g_resource_dispatcher_host = NULL;
}

// static
ResourceDispatcherHostImpl* ResourceDispatcherHostImpl::Get() {
  return g_resource_dispatcher_host;
}

void ResourceDispatcherHostImpl::SetDelegate(
    ResourceDispatcherHostDelegate* delegate) {
  delegate_ = delegate;
}

void ResourceDispatcherHostImpl::SetAllowCrossOriginAuthPrompt(bool value) {
  allow_cross_origin_auth_prompt_ = value;
}

void ResourceDispatcherHostImpl::AddResourceContext(ResourceContext* context) {
  active_resource_contexts_.insert(context);
}

void ResourceDispatcherHostImpl::RemoveResourceContext(
    ResourceContext* context) {
  CHECK(ContainsKey(active_resource_contexts_, context));
  active_resource_contexts_.erase(context);
}

void ResourceDispatcherHostImpl::CancelRequestsForContext(
    ResourceContext* context) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
  DCHECK(context);

  CHECK(ContainsKey(active_resource_contexts_, context));

  // Note that request cancellation has side effects. Therefore, we gather all
  // the requests to cancel first, and then we start cancelling. We assert at
  // the end that there are no more to cancel since the context is about to go
  // away.
  typedef std::vector<linked_ptr<ResourceLoader> > LoaderList;
  LoaderList loaders_to_cancel;

  for (LoaderMap::iterator i = pending_loaders_.begin();
       i != pending_loaders_.end();) {
    if (i->second->GetRequestInfo()->GetContext() == context) {
      loaders_to_cancel.push_back(i->second);
      IncrementOutstandingRequestsMemory(-1, *i->second->GetRequestInfo());
      pending_loaders_.erase(i++);
    } else {
      ++i;
    }
  }

  for (BlockedLoadersMap::iterator i = blocked_loaders_map_.begin();
       i != blocked_loaders_map_.end();) {
    BlockedLoadersList* loaders = i->second;
    if (loaders->empty()) {
      // This can happen if BlockRequestsForRoute() has been called for a route,
      // but we haven't blocked any matching requests yet.
      ++i;
      continue;
    }
    ResourceRequestInfoImpl* info = loaders->front()->GetRequestInfo();
    if (info->GetContext() == context) {
      blocked_loaders_map_.erase(i++);
      for (BlockedLoadersList::const_iterator it = loaders->begin();
           it != loaders->end(); ++it) {
        linked_ptr<ResourceLoader> loader = *it;
        info = loader->GetRequestInfo();
        // We make the assumption that all requests on the list have the same
        // ResourceContext.
        DCHECK_EQ(context, info->GetContext());
        IncrementOutstandingRequestsMemory(-1, *info);
        loaders_to_cancel.push_back(loader);
      }
      delete loaders;
    } else {
      ++i;
    }
  }

#ifndef NDEBUG
  for (LoaderList::iterator i = loaders_to_cancel.begin();
       i != loaders_to_cancel.end(); ++i) {
    // There is no strict requirement that this be the case, but currently
    // downloads, streams, detachable requests, and transferred requests are the
    // only requests that aren't cancelled when the associated processes go
    // away. It may be OK for this invariant to change in the future, but if
    // this assertion fires without the invariant changing, then it's indicative
    // of a leak.
    DCHECK((*i)->GetRequestInfo()->IsDownload() ||
           (*i)->GetRequestInfo()->is_stream() ||
           ((*i)->GetRequestInfo()->detachable_handler() &&
            (*i)->GetRequestInfo()->detachable_handler()->is_detached()) ||
           (*i)->is_transferring());
  }
#endif

  loaders_to_cancel.clear();

  // Validate that no more requests for this context were added.
  for (LoaderMap::const_iterator i = pending_loaders_.begin();
       i != pending_loaders_.end(); ++i) {
    // http://crbug.com/90971
    CHECK_NE(i->second->GetRequestInfo()->GetContext(), context);
  }

  for (BlockedLoadersMap::const_iterator i = blocked_loaders_map_.begin();
       i != blocked_loaders_map_.end(); ++i) {
    BlockedLoadersList* loaders = i->second;
    if (!loaders->empty()) {
      ResourceRequestInfoImpl* info = loaders->front()->GetRequestInfo();
      // http://crbug.com/90971
      CHECK_NE(info->GetContext(), context);
    }
  }
}

DownloadInterruptReason ResourceDispatcherHostImpl::BeginDownload(
    scoped_ptr<net::URLRequest> request,
    const Referrer& referrer,
    bool is_content_initiated,
    ResourceContext* context,
    int child_id,
    int route_id,
    bool prefer_cache,
    scoped_ptr<DownloadSaveInfo> save_info,
    uint32 download_id,
    const DownloadStartedCallback& started_callback) {
  if (is_shutdown_)
    return CallbackAndReturn(started_callback,
                             DOWNLOAD_INTERRUPT_REASON_USER_SHUTDOWN);

  const GURL& url = request->original_url();

  // http://crbug.com/90971
  char url_buf[128];
  base::strlcpy(url_buf, url.spec().c_str(), arraysize(url_buf));
  base::debug::Alias(url_buf);
  CHECK(ContainsKey(active_resource_contexts_, context));

  SetReferrerForRequest(request.get(), referrer);

  int extra_load_flags = net::LOAD_IS_DOWNLOAD;
  if (prefer_cache) {
    // If there is upload data attached, only retrieve from cache because there
    // is no current mechanism to prompt the user for their consent for a
    // re-post. For GETs, try to retrieve data from the cache and skip
    // validating the entry if present.
    if (request->get_upload() != NULL)
      extra_load_flags |= net::LOAD_ONLY_FROM_CACHE;
    else
      extra_load_flags |= net::LOAD_PREFERRING_CACHE;
  } else {
    extra_load_flags |= net::LOAD_DISABLE_CACHE;
  }
  request->SetLoadFlags(request->load_flags() | extra_load_flags);

  // No need to get offline load flags for downloads, but make sure
  // we have an OfflinePolicy to receive request completions.
  GlobalRoutingID id(child_id, route_id);
  if (!offline_policy_map_[id])
    offline_policy_map_[id] = new OfflinePolicy();

  // Check if the renderer is permitted to request the requested URL.
  if (!ChildProcessSecurityPolicyImpl::GetInstance()->
          CanRequestURL(child_id, url)) {
    VLOG(1) << "Denied unauthorized download request for "
            << url.possibly_invalid_spec();
    return CallbackAndReturn(started_callback,
                             DOWNLOAD_INTERRUPT_REASON_NETWORK_INVALID_REQUEST);
  }

  request_id_--;

  const net::URLRequestContext* request_context = context->GetRequestContext();
  if (!request_context->job_factory()->IsHandledURL(url)) {
    VLOG(1) << "Download request for unsupported protocol: "
            << url.possibly_invalid_spec();
    return CallbackAndReturn(started_callback,
                             DOWNLOAD_INTERRUPT_REASON_NETWORK_INVALID_REQUEST);
  }

  ResourceRequestInfoImpl* extra_info =
      CreateRequestInfo(child_id, route_id, true, context);
  extra_info->AssociateWithRequest(request.get());  // Request takes ownership.

  if (request->url().SchemeIs(kBlobScheme)) {
    ChromeBlobStorageContext* blob_context =
        GetChromeBlobStorageContextForResourceContext(context);
    webkit_blob::BlobProtocolHandler::SetRequestedBlobDataHandle(
        request.get(),
        blob_context->context()->GetBlobDataFromPublicURL(request->url()));
  }

  // From this point forward, the |DownloadResourceHandler| is responsible for
  // |started_callback|.
  scoped_ptr<ResourceHandler> handler(
      CreateResourceHandlerForDownload(request.get(), is_content_initiated,
                                       true, download_id, save_info.Pass(),
                                       started_callback));

  BeginRequestInternal(request.Pass(), handler.Pass());

  return DOWNLOAD_INTERRUPT_REASON_NONE;
}

void ResourceDispatcherHostImpl::ClearLoginDelegateForRequest(
    net::URLRequest* request) {
  ResourceRequestInfoImpl* info = ResourceRequestInfoImpl::ForRequest(request);
  if (info) {
    ResourceLoader* loader = GetLoader(info->GetGlobalRequestID());
    if (loader)
      loader->ClearLoginDelegate();
  }
}

void ResourceDispatcherHostImpl::Shutdown() {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  BrowserThread::PostTask(BrowserThread::IO,
                          FROM_HERE,
                          base::Bind(&ResourceDispatcherHostImpl::OnShutdown,
                                     base::Unretained(this)));
}

scoped_ptr<ResourceHandler>
ResourceDispatcherHostImpl::CreateResourceHandlerForDownload(
    net::URLRequest* request,
    bool is_content_initiated,
    bool must_download,
    uint32 id,
    scoped_ptr<DownloadSaveInfo> save_info,
    const DownloadUrlParameters::OnStartedCallback& started_cb) {
  scoped_ptr<ResourceHandler> handler(
      new DownloadResourceHandler(id, request, started_cb, save_info.Pass()));
  if (delegate_) {
    const ResourceRequestInfo* request_info(
        ResourceRequestInfo::ForRequest(request));

    ScopedVector<ResourceThrottle> throttles;
    delegate_->DownloadStarting(
        request, request_info->GetContext(), request_info->GetChildID(),
        request_info->GetRouteID(), request_info->GetRequestID(),
        is_content_initiated, must_download, &throttles);
    if (!throttles.empty()) {
      handler.reset(
          new ThrottlingResourceHandler(
              handler.Pass(), request, throttles.Pass()));
    }
  }
  return handler.Pass();
}

scoped_ptr<ResourceHandler>
ResourceDispatcherHostImpl::MaybeInterceptAsStream(net::URLRequest* request,
                                                   ResourceResponse* response) {
  ResourceRequestInfoImpl* info = ResourceRequestInfoImpl::ForRequest(request);
  const std::string& mime_type = response->head.mime_type;

  GURL origin;
  std::string target_id;
  if (!delegate_ ||
      !delegate_->ShouldInterceptResourceAsStream(info->GetContext(),
                                                  request->url(),
                                                  mime_type,
                                                  &origin,
                                                  &target_id)) {
    return scoped_ptr<ResourceHandler>();
  }

  StreamContext* stream_context =
      GetStreamContextForResourceContext(info->GetContext());

  scoped_ptr<StreamResourceHandler> handler(
      new StreamResourceHandler(request,
                                stream_context->registry(),
                                origin));

  info->set_is_stream(true);
  delegate_->OnStreamCreated(
      info->GetContext(),
      info->GetChildID(),
      info->GetRouteID(),
      target_id,
      handler->stream()->CreateHandle(
          request->url(),
          mime_type,
          response->head.headers),
      request->GetExpectedContentSize());
  return handler.PassAs<ResourceHandler>();
}

void ResourceDispatcherHostImpl::ClearSSLClientAuthHandlerForRequest(
    net::URLRequest* request) {
  ResourceRequestInfoImpl* info = ResourceRequestInfoImpl::ForRequest(request);
  if (info) {
    ResourceLoader* loader = GetLoader(info->GetGlobalRequestID());
    if (loader)
      loader->ClearSSLClientAuthHandler();
  }
}

ResourceDispatcherHostLoginDelegate*
ResourceDispatcherHostImpl::CreateLoginDelegate(
    ResourceLoader* loader,
    net::AuthChallengeInfo* auth_info) {
  if (!delegate_)
    return NULL;

  return delegate_->CreateLoginDelegate(auth_info, loader->request());
}

bool ResourceDispatcherHostImpl::HandleExternalProtocol(ResourceLoader* loader,
                                                        const GURL& url) {
  if (!delegate_)
    return false;

  ResourceRequestInfoImpl* info = loader->GetRequestInfo();

  if (!ResourceType::IsFrame(info->GetResourceType()))
    return false;

  const net::URLRequestJobFactory* job_factory =
      info->GetContext()->GetRequestContext()->job_factory();
  if (job_factory->IsHandledURL(url))
    return false;

  bool initiated_by_user_gesture =
      (loader->request()->load_flags() & net::LOAD_MAYBE_USER_GESTURE) != 0;
  bool handled = delegate_->HandleExternalProtocol(url, info->GetChildID(),
                                                   info->GetRouteID(),
                                                   initiated_by_user_gesture);
  // Consume the user gesture if the external protocol dialog is shown.
  if (handled)
    last_user_gesture_time_ = base::TimeTicks();
  return handled;
}

void ResourceDispatcherHostImpl::DidStartRequest(ResourceLoader* loader) {
  // Make sure we have the load state monitor running
  if (!update_load_states_timer_->IsRunning()) {
    update_load_states_timer_->Start(FROM_HERE,
        TimeDelta::FromMilliseconds(kUpdateLoadStatesIntervalMsec),
        this, &ResourceDispatcherHostImpl::UpdateLoadStates);
  }
}

void ResourceDispatcherHostImpl::DidReceiveRedirect(ResourceLoader* loader,
                                                    const GURL& new_url) {
  ResourceRequestInfoImpl* info = loader->GetRequestInfo();

  int render_process_id, render_frame_host;
  if (!info->GetAssociatedRenderFrame(&render_process_id, &render_frame_host))
    return;

  // Notify the observers on the UI thread.
  scoped_ptr<ResourceRedirectDetails> detail(new ResourceRedirectDetails(
      loader->request(),
      GetCertID(loader->request(), info->GetChildID()),
      new_url));
  BrowserThread::PostTask(
      BrowserThread::UI, FROM_HERE,
      base::Bind(
          &NotifyRedirectOnUI,
          render_process_id, render_frame_host, base::Passed(&detail)));
}

void ResourceDispatcherHostImpl::DidReceiveResponse(ResourceLoader* loader) {
  ResourceRequestInfoImpl* info = loader->GetRequestInfo();

  if (loader->request()->was_fetched_via_proxy() &&
      loader->request()->was_fetched_via_spdy() &&
      loader->request()->url().SchemeIs("http")) {
    scheduler_->OnReceivedSpdyProxiedHttpResponse(
        info->GetChildID(), info->GetRouteID());
  }

  // There should be an entry in the map created when we dispatched the
  // request unless it's been detached and the renderer has died.
  OfflineMap::iterator policy_it(
      offline_policy_map_.find(info->GetGlobalRoutingID()));
  if (offline_policy_map_.end() != policy_it) {
    policy_it->second->UpdateStateForSuccessfullyStartedRequest(
        loader->request()->response_info());
  } else {
    // Unless detached, we should have an entry in offline_policy_map_ from
    // when this request traversed Begin{Download,SaveFile,Request}.
    // TODO(rdsmith): This isn't currently true; see http://crbug.com/241176.
    DCHECK(info->detachable_handler() &&
           info->detachable_handler()->is_detached());
  }

  int render_process_id, render_frame_host;
  if (!info->GetAssociatedRenderFrame(&render_process_id, &render_frame_host))
    return;

  // Notify the observers on the UI thread.
  scoped_ptr<ResourceRequestDetails> detail(new ResourceRequestDetails(
      loader->request(),
      GetCertID(loader->request(), info->GetChildID())));
  BrowserThread::PostTask(
      BrowserThread::UI, FROM_HERE,
      base::Bind(
          &NotifyResponseOnUI,
          render_process_id, render_frame_host, base::Passed(&detail)));
}

void ResourceDispatcherHostImpl::DidFinishLoading(ResourceLoader* loader) {
  ResourceRequestInfo* info = loader->GetRequestInfo();

  // Record final result of all resource loads.
  if (info->GetResourceType() == ResourceType::MAIN_FRAME) {
    // This enumeration has "3" appended to its name to distinguish it from
    // older versions.
    UMA_HISTOGRAM_SPARSE_SLOWLY(
        "Net.ErrorCodesForMainFrame3",
        -loader->request()->status().error());

    if (loader->request()->url().SchemeIsSecure()) {
      if (loader->request()->url().host() == "www.google.com") {
        UMA_HISTOGRAM_SPARSE_SLOWLY("Net.ErrorCodesForHTTPSGoogleMainFrame2",
                                    -loader->request()->status().error());
      }

      int num_valid_scts = std::count_if(
          loader->request()->ssl_info().signed_certificate_timestamps.begin(),
          loader->request()->ssl_info().signed_certificate_timestamps.end(),
          IsValidatedSCT);
      UMA_HISTOGRAM_COUNTS_100(
          "Net.CertificateTransparency.MainFrameValidSCTCount", num_valid_scts);
    }
  } else {
    if (info->GetResourceType() == ResourceType::IMAGE) {
      UMA_HISTOGRAM_SPARSE_SLOWLY(
          "Net.ErrorCodesForImages",
          -loader->request()->status().error());
    }
    // This enumeration has "2" appended to distinguish it from older versions.
    UMA_HISTOGRAM_SPARSE_SLOWLY(
        "Net.ErrorCodesForSubresources2",
        -loader->request()->status().error());
  }

  if (delegate_)
    delegate_->RequestComplete(loader->request());

  // Destroy the ResourceLoader.
  RemovePendingRequest(info->GetChildID(), info->GetRequestID());
}

void ResourceDispatcherHostImpl::OnInit() {
  scheduler_.reset(new ResourceScheduler);
  AppCacheInterceptor::EnsureRegistered();
}

void ResourceDispatcherHostImpl::OnShutdown() {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));

  is_shutdown_ = true;
  pending_loaders_.clear();

  // Make sure we shutdown the timer now, otherwise by the time our destructor
  // runs if the timer is still running the Task is deleted twice (once by
  // the MessageLoop and the second time by RepeatingTimer).
  update_load_states_timer_.reset();

  // Clear blocked requests if any left.
  // Note that we have to do this in 2 passes as we cannot call
  // CancelBlockedRequestsForRoute while iterating over
  // blocked_loaders_map_, as it modifies it.
  std::set<GlobalRoutingID> ids;
  for (BlockedLoadersMap::const_iterator iter = blocked_loaders_map_.begin();
       iter != blocked_loaders_map_.end(); ++iter) {
    std::pair<std::set<GlobalRoutingID>::iterator, bool> result =
        ids.insert(iter->first);
    // We should not have duplicates.
    DCHECK(result.second);
  }
  for (std::set<GlobalRoutingID>::const_iterator iter = ids.begin();
       iter != ids.end(); ++iter) {
    CancelBlockedRequestsForRoute(iter->child_id, iter->route_id);
  }

  scheduler_.reset();
}

bool ResourceDispatcherHostImpl::OnMessageReceived(
    const IPC::Message& message,
    ResourceMessageFilter* filter,
    bool* message_was_ok) {
  filter_ = filter;
  bool handled = true;
  IPC_BEGIN_MESSAGE_MAP_EX(ResourceDispatcherHostImpl, message, *message_was_ok)
    IPC_MESSAGE_HANDLER(ResourceHostMsg_RequestResource, OnRequestResource)
    IPC_MESSAGE_HANDLER_DELAY_REPLY(ResourceHostMsg_SyncLoad, OnSyncLoad)
    IPC_MESSAGE_HANDLER(ResourceHostMsg_ReleaseDownloadedFile,
                        OnReleaseDownloadedFile)
    IPC_MESSAGE_HANDLER(ResourceHostMsg_DataDownloaded_ACK, OnDataDownloadedACK)
    IPC_MESSAGE_HANDLER(ResourceHostMsg_UploadProgress_ACK, OnUploadProgressACK)
    IPC_MESSAGE_HANDLER(ResourceHostMsg_CancelRequest, OnCancelRequest)
    IPC_MESSAGE_UNHANDLED(handled = false)
  IPC_END_MESSAGE_MAP_EX()

  if (!handled && IPC_MESSAGE_ID_CLASS(message.type()) == ResourceMsgStart) {
    PickleIterator iter(message);
    int request_id = -1;
    bool ok = iter.ReadInt(&request_id);
    DCHECK(ok);
    GlobalRequestID id(filter_->child_id(), request_id);
    DelegateMap::iterator it = delegate_map_.find(id);
    if (it != delegate_map_.end()) {
      ObserverList<ResourceMessageDelegate>::Iterator del_it(*it->second);
      ResourceMessageDelegate* delegate;
      while (!handled && (delegate = del_it.GetNext()) != NULL) {
        handled = delegate->OnMessageReceived(message, message_was_ok);
      }
    }

    // As the unhandled resource message effectively has no consumer, mark it as
    // handled to prevent needless propagation through the filter pipeline.
    handled = true;
  }

  filter_ = NULL;
  return handled;
}

void ResourceDispatcherHostImpl::OnRequestResource(
    const IPC::Message& message,
    int request_id,
    const ResourceHostMsg_Request& request_data) {
  BeginRequest(request_id, request_data, NULL, message.routing_id());
}

// Begins a resource request with the given params on behalf of the specified
// child process.  Responses will be dispatched through the given receiver. The
// process ID is used to lookup WebContentsImpl from routing_id's in the case of
// a request from a renderer.  request_context is the cookie/cache context to be
// used for this request.
//
// If sync_result is non-null, then a SyncLoad reply will be generated, else
// a normal asynchronous set of response messages will be generated.
void ResourceDispatcherHostImpl::OnSyncLoad(
    int request_id,
    const ResourceHostMsg_Request& request_data,
    IPC::Message* sync_result) {
  BeginRequest(request_id, request_data, sync_result,
               sync_result->routing_id());
}

void ResourceDispatcherHostImpl::UpdateRequestForTransfer(
    int child_id,
    int route_id,
    int request_id,
    const ResourceHostMsg_Request& request_data,
    const linked_ptr<ResourceLoader>& loader) {
  ResourceRequestInfoImpl* info = loader->GetRequestInfo();
  GlobalRoutingID old_routing_id(
      request_data.transferred_request_child_id, info->GetRouteID());
  GlobalRequestID old_request_id(request_data.transferred_request_child_id,
                                 request_data.transferred_request_request_id);
  GlobalRoutingID new_routing_id(child_id, route_id);
  GlobalRequestID new_request_id(child_id, request_id);

  // Clear out data that depends on |info| before updating it.
  IncrementOutstandingRequestsMemory(-1, *info);
  OustandingRequestsStats empty_stats = { 0, 0 };
  OustandingRequestsStats old_stats = GetOutstandingRequestsStats(*info);
  UpdateOutstandingRequestsStats(*info, empty_stats);
  pending_loaders_.erase(old_request_id);

  // ResourceHandlers should always get state related to the request from the
  // ResourceRequestInfo rather than caching it locally.  This lets us update
  // the info object when a transfer occurs.
  info->UpdateForTransfer(child_id, route_id, request_data.origin_pid,
                          request_id, request_data.parent_render_frame_id,
                          filter_->GetWeakPtr());

  // Update maps that used the old IDs, if necessary.  Some transfers in tests
  // do not actually use a different ID, so not all maps need to be updated.
  pending_loaders_[new_request_id] = loader;
  UpdateOutstandingRequestsStats(*info, old_stats);
  IncrementOutstandingRequestsMemory(1, *info);
  if (old_routing_id != new_routing_id) {
    if (offline_policy_map_.find(old_routing_id) != offline_policy_map_.end()) {
      if (offline_policy_map_.find(new_routing_id) !=
          offline_policy_map_.end())
        delete offline_policy_map_[new_routing_id];
      offline_policy_map_[new_routing_id] = offline_policy_map_[old_routing_id];
      offline_policy_map_.erase(old_routing_id);
    }
    if (blocked_loaders_map_.find(old_routing_id) !=
            blocked_loaders_map_.end()) {
      blocked_loaders_map_[new_routing_id] =
          blocked_loaders_map_[old_routing_id];
      blocked_loaders_map_.erase(old_routing_id);
    }
  }
  if (old_request_id != new_request_id) {
    DelegateMap::iterator it = delegate_map_.find(old_request_id);
    if (it != delegate_map_.end()) {
      // Tell each delegate that the request ID has changed.
      ObserverList<ResourceMessageDelegate>::Iterator del_it(*it->second);
      ResourceMessageDelegate* delegate;
      while ((delegate = del_it.GetNext()) != NULL) {
        delegate->set_request_id(new_request_id);
      }
      // Now store the observer list under the new request ID.
      delegate_map_[new_request_id] = delegate_map_[old_request_id];
      delegate_map_.erase(old_request_id);
    }
  }

  AppCacheInterceptor::CompleteCrossSiteTransfer(
      loader->request(),
      child_id,
      request_data.appcache_host_id);

  // We should have a CrossSiteResourceHandler to finish the transfer.
  DCHECK(info->cross_site_handler());
}

void ResourceDispatcherHostImpl::BeginRequest(
    int request_id,
    const ResourceHostMsg_Request& request_data,
    IPC::Message* sync_result,  // only valid for sync
    int route_id) {
  int process_type = filter_->process_type();
  int child_id = filter_->child_id();

  // Reject invalid priority.
  if (request_data.priority < net::MINIMUM_PRIORITY ||
      request_data.priority > net::MAXIMUM_PRIORITY) {
    RecordAction(base::UserMetricsAction("BadMessageTerminate_RDH"));
    filter_->BadMessageReceived();
    return;
  }

  // If we crash here, figure out what URL the renderer was requesting.
  // http://crbug.com/91398
  char url_buf[128];
  base::strlcpy(url_buf, request_data.url.spec().c_str(), arraysize(url_buf));
  base::debug::Alias(url_buf);

  // If the request that's coming in is being transferred from another process,
  // we want to reuse and resume the old loader rather than start a new one.
  {
    LoaderMap::iterator it = pending_loaders_.find(
        GlobalRequestID(request_data.transferred_request_child_id,
                        request_data.transferred_request_request_id));
    if (it != pending_loaders_.end()) {
      // If the request is transferring to a new process, we can update our
      // state and let it resume with its existing ResourceHandlers.
      if (it->second->is_transferring()) {
        linked_ptr<ResourceLoader> deferred_loader = it->second;
        UpdateRequestForTransfer(child_id, route_id, request_id,
                                 request_data, deferred_loader);

        deferred_loader->CompleteTransfer();
      } else {
        RecordAction(base::UserMetricsAction("BadMessageTerminate_RDH"));
        filter_->BadMessageReceived();
      }
      return;
    }
  }

  ResourceContext* resource_context = NULL;
  net::URLRequestContext* request_context = NULL;
  filter_->GetContexts(request_data, &resource_context, &request_context);
  // http://crbug.com/90971
  CHECK(ContainsKey(active_resource_contexts_, resource_context));

  if (is_shutdown_ ||
      !ShouldServiceRequest(process_type, child_id, request_data,
                            filter_->file_system_context())) {
    AbortRequestBeforeItStarts(filter_, sync_result, request_id);
    return;
  }

  // Allow the observer to block/handle the request.
  if (delegate_ && !delegate_->ShouldBeginRequest(child_id,
                                                  route_id,
                                                  request_data.method,
                                                  request_data.url,
                                                  request_data.resource_type,
                                                  resource_context)) {
    AbortRequestBeforeItStarts(filter_, sync_result, request_id);
    return;
  }

  bool is_sync_load = sync_result != NULL;
  int load_flags =
      BuildLoadFlagsForRequest(request_data, child_id, is_sync_load);

  GlobalRoutingID id(child_id, route_id);
  if (!offline_policy_map_[id])
    offline_policy_map_[id] = new OfflinePolicy();
  load_flags |= offline_policy_map_[id]->GetAdditionalLoadFlags(
      load_flags, request_data.resource_type == ResourceType::MAIN_FRAME);

  // Sync loads should have maximum priority and should be the only
  // requets that have the ignore limits flag set.
  if (is_sync_load) {
    DCHECK_EQ(request_data.priority, net::MAXIMUM_PRIORITY);
    DCHECK_NE(load_flags & net::LOAD_IGNORE_LIMITS, 0);
  } else {
    DCHECK_EQ(load_flags & net::LOAD_IGNORE_LIMITS, 0);
  }

  // Construct the request.
  net::CookieStore* cookie_store =
      GetContentClient()->browser()->OverrideCookieStoreForRenderProcess(
          child_id);
  scoped_ptr<net::URLRequest> new_request;
  new_request = request_context->CreateRequest(
      request_data.url, request_data.priority, NULL, cookie_store);

  new_request->set_method(request_data.method);
  new_request->set_first_party_for_cookies(
      request_data.first_party_for_cookies);

  const Referrer referrer(request_data.referrer, request_data.referrer_policy);
  SetReferrerForRequest(new_request.get(), referrer);

  net::HttpRequestHeaders headers;
  headers.AddHeadersFromString(request_data.headers);
  new_request->SetExtraRequestHeaders(headers);

  new_request->SetLoadFlags(load_flags);

  // Resolve elements from request_body and prepare upload data.
  if (request_data.request_body.get()) {
    webkit_blob::BlobStorageContext* blob_context = NULL;
    if (filter_->blob_storage_context())
      blob_context = filter_->blob_storage_context()->context();
    new_request->set_upload(UploadDataStreamBuilder::Build(
        request_data.request_body.get(),
        blob_context,
        filter_->file_system_context(),
        BrowserThread::GetMessageLoopProxyForThread(BrowserThread::FILE)
            .get()));
  }

  bool allow_download = request_data.allow_download &&
      ResourceType::IsFrame(request_data.resource_type);

  // Make extra info and read footer (contains request ID).
  ResourceRequestInfoImpl* extra_info =
      new ResourceRequestInfoImpl(
          process_type,
          child_id,
          route_id,
          request_data.origin_pid,
          request_id,
          request_data.render_frame_id,
          request_data.is_main_frame,
          request_data.parent_is_main_frame,
          request_data.parent_render_frame_id,
          request_data.resource_type,
          request_data.transition_type,
          request_data.should_replace_current_entry,
          false,  // is download
          false,  // is stream
          allow_download,
          request_data.has_user_gesture,
          request_data.referrer_policy,
          request_data.visiblity_state,
          resource_context,
          filter_->GetWeakPtr(),
          !is_sync_load);
  // Request takes ownership.
  extra_info->AssociateWithRequest(new_request.get());

  if (new_request->url().SchemeIs(kBlobScheme)) {
    // Hang on to a reference to ensure the blob is not released prior
    // to the job being started.
    webkit_blob::BlobProtocolHandler::SetRequestedBlobDataHandle(
        new_request.get(),
        filter_->blob_storage_context()->context()->
            GetBlobDataFromPublicURL(new_request->url()));
  }

  // Initialize the service worker handler for the request.
  ServiceWorkerRequestHandler::InitializeHandler(
      new_request.get(),
      filter_->service_worker_context(),
      child_id,
      request_data.service_worker_provider_id,
      request_data.resource_type);

  // Have the appcache associate its extra info with the request.
  AppCacheInterceptor::SetExtraRequestInfo(
      new_request.get(), filter_->appcache_service(), child_id,
      request_data.appcache_host_id, request_data.resource_type);

  scoped_ptr<ResourceHandler> handler(
       CreateResourceHandler(
           new_request.get(),
           request_data, sync_result, route_id, process_type, child_id,
           resource_context));

  if (handler)
    BeginRequestInternal(new_request.Pass(), handler.Pass());
}

scoped_ptr<ResourceHandler> ResourceDispatcherHostImpl::CreateResourceHandler(
    net::URLRequest* request,
    const ResourceHostMsg_Request& request_data,
    IPC::Message* sync_result,
    int route_id,
    int process_type,
    int child_id,
    ResourceContext* resource_context) {
  // Construct the IPC resource handler.
  scoped_ptr<ResourceHandler> handler;
  if (sync_result) {
    // download_to_file is not supported for synchronous requests.
    if (request_data.download_to_file) {
      RecordAction(base::UserMetricsAction("BadMessageTerminate_RDH"));
      filter_->BadMessageReceived();
      return scoped_ptr<ResourceHandler>();
    }

    handler.reset(new SyncResourceHandler(request, sync_result, this));
  } else {
    handler.reset(new AsyncResourceHandler(request, this));

    // The RedirectToFileResourceHandler depends on being next in the chain.
    if (request_data.download_to_file) {
      handler.reset(
          new RedirectToFileResourceHandler(handler.Pass(), request));
    }
  }

  // Prefetches and <a ping> requests outlive their child process.
  if (!sync_result && IsDetachableResourceType(request_data.resource_type)) {
    handler.reset(new DetachableResourceHandler(
        request,
        base::TimeDelta::FromMilliseconds(kDefaultDetachableCancelDelayMs),
        handler.Pass()));
  }

  // Install a CrossSiteResourceHandler for all main frame requests.  This will
  // let us check whether a transfer is required and pause for the unload
  // handler either if so or if a cross-process navigation is already under way.
  bool is_swappable_navigation =
      request_data.resource_type == ResourceType::MAIN_FRAME;
  // If we are using --site-per-process, install it for subframes as well.
  if (!is_swappable_navigation &&
      CommandLine::ForCurrentProcess()->HasSwitch(switches::kSitePerProcess)) {
    is_swappable_navigation =
        request_data.resource_type == ResourceType::SUB_FRAME;
  }
  if (is_swappable_navigation && process_type == PROCESS_TYPE_RENDERER)
    handler.reset(new CrossSiteResourceHandler(handler.Pass(), request));

  // Insert a buffered event handler before the actual one.
  handler.reset(
      new BufferedResourceHandler(handler.Pass(), this, request));

  ScopedVector<ResourceThrottle> throttles;
  if (delegate_) {
    delegate_->RequestBeginning(request,
                                resource_context,
                                filter_->appcache_service(),
                                request_data.resource_type,
                                child_id,
                                route_id,
                                &throttles);
  }

  if (request->has_upload()) {
    // Block power save while uploading data.
    throttles.push_back(new PowerSaveBlockResourceThrottle());
  }

  throttles.push_back(
      scheduler_->ScheduleRequest(child_id, route_id, request).release());

  handler.reset(
      new ThrottlingResourceHandler(handler.Pass(), request, throttles.Pass()));

  return handler.Pass();
}

void ResourceDispatcherHostImpl::OnReleaseDownloadedFile(int request_id) {
  UnregisterDownloadedTempFile(filter_->child_id(), request_id);
}

void ResourceDispatcherHostImpl::OnDataDownloadedACK(int request_id) {
  // TODO(michaeln): maybe throttle DataDownloaded messages
}

void ResourceDispatcherHostImpl::RegisterDownloadedTempFile(
    int child_id, int request_id, const base::FilePath& file_path) {
  scoped_refptr<ShareableFileReference> reference =
      ShareableFileReference::Get(file_path);
  DCHECK(reference);

  registered_temp_files_[child_id][request_id] = reference;
  ChildProcessSecurityPolicyImpl::GetInstance()->GrantReadFile(
      child_id, reference->path());

  // When the temp file is deleted, revoke permissions that the renderer has
  // to that file. This covers an edge case where the file is deleted and then
  // the same name is re-used for some other purpose, we don't want the old
  // renderer to still have access to it.
  //
  // We do this when the file is deleted because the renderer can take a blob
  // reference to the temp file that outlives the url loaded that it was
  // loaded with to keep the file (and permissions) alive.
  reference->AddFinalReleaseCallback(
      base::Bind(&RemoveDownloadFileFromChildSecurityPolicy,
                 child_id));
}

void ResourceDispatcherHostImpl::UnregisterDownloadedTempFile(
    int child_id, int request_id) {
  DeletableFilesMap& map = registered_temp_files_[child_id];
  DeletableFilesMap::iterator found = map.find(request_id);
  if (found == map.end())
    return;

  map.erase(found);

  // Note that we don't remove the security bits here. This will be done
  // when all file refs are deleted (see RegisterDownloadedTempFile).
}

bool ResourceDispatcherHostImpl::Send(IPC::Message* message) {
  delete message;
  return false;
}

void ResourceDispatcherHostImpl::OnUploadProgressACK(int request_id) {
  ResourceLoader* loader = GetLoader(filter_->child_id(), request_id);
  if (loader)
    loader->OnUploadProgressACK();
}

// Note that this cancel is subtly different from the other
// CancelRequest methods in this file, which also tear down the loader.
void ResourceDispatcherHostImpl::OnCancelRequest(int request_id) {
  int child_id = filter_->child_id();

  // When the old renderer dies, it sends a message to us to cancel its
  // requests.
  if (IsTransferredNavigation(GlobalRequestID(child_id, request_id)))
    return;

  ResourceLoader* loader = GetLoader(child_id, request_id);
  if (!loader) {
    // We probably want to remove this warning eventually, but I wanted to be
    // able to notice when this happens during initial development since it
    // should be rare and may indicate a bug.
    DVLOG(1) << "Canceling a request that wasn't found";
    return;
  }

  loader->CancelRequest(true);
}

ResourceRequestInfoImpl* ResourceDispatcherHostImpl::CreateRequestInfo(
    int child_id,
    int route_id,
    bool download,
    ResourceContext* context) {
  return new ResourceRequestInfoImpl(
      PROCESS_TYPE_RENDERER,
      child_id,
      route_id,
      0,
      request_id_,
      MSG_ROUTING_NONE,  // render_frame_id
      false,     // is_main_frame
      false,     // parent_is_main_frame
      -1,        // parent_render_frame_id
      ResourceType::SUB_RESOURCE,
      PAGE_TRANSITION_LINK,
      false,     // should_replace_current_entry
      download,  // is_download
      false,     // is_stream
      download,  // allow_download
      false,     // has_user_gesture
      blink::WebReferrerPolicyDefault,
      blink::WebPageVisibilityStateVisible,
      context,
      base::WeakPtr<ResourceMessageFilter>(),  // filter
      true);     // is_async
}

void ResourceDispatcherHostImpl::OnRenderViewHostCreated(
    int child_id,
    int route_id) {
  scheduler_->OnClientCreated(child_id, route_id);
}

void ResourceDispatcherHostImpl::OnRenderViewHostDeleted(
    int child_id,
    int route_id) {
  scheduler_->OnClientDeleted(child_id, route_id);
  CancelRequestsForRoute(child_id, route_id);
}

// This function is only used for saving feature.
void ResourceDispatcherHostImpl::BeginSaveFile(
    const GURL& url,
    const Referrer& referrer,
    int child_id,
    int route_id,
    ResourceContext* context) {
  if (is_shutdown_)
    return;

  // http://crbug.com/90971
  char url_buf[128];
  base::strlcpy(url_buf, url.spec().c_str(), arraysize(url_buf));
  base::debug::Alias(url_buf);
  CHECK(ContainsKey(active_resource_contexts_, context));

  scoped_ptr<ResourceHandler> handler(
      new SaveFileResourceHandler(child_id,
                                  route_id,
                                  url,
                                  save_file_manager_.get()));
  request_id_--;

  const net::URLRequestContext* request_context = context->GetRequestContext();
  bool known_proto =
      request_context->job_factory()->IsHandledURL(url);
  if (!known_proto) {
    // Since any URLs which have non-standard scheme have been filtered
    // by save manager(see GURL::SchemeIsStandard). This situation
    // should not happen.
    NOTREACHED();
    return;
  }

  net::CookieStore* cookie_store =
      GetContentClient()->browser()->OverrideCookieStoreForRenderProcess(
          child_id);
  scoped_ptr<net::URLRequest> request(
      request_context->CreateRequest(url, net::DEFAULT_PRIORITY, NULL,
                                     cookie_store));

  request->set_method("GET");
  SetReferrerForRequest(request.get(), referrer);

  // So far, for saving page, we need fetch content from cache, in the
  // future, maybe we can use a configuration to configure this behavior.
  request->SetLoadFlags(net::LOAD_PREFERRING_CACHE);

  // No need to get offline load flags for save files, but make sure
  // we have an OfflinePolicy to receive request completions.
  GlobalRoutingID id(child_id, route_id);
  if (!offline_policy_map_[id])
    offline_policy_map_[id] = new OfflinePolicy();

  // Since we're just saving some resources we need, disallow downloading.
  ResourceRequestInfoImpl* extra_info =
      CreateRequestInfo(child_id, route_id, false, context);
  extra_info->AssociateWithRequest(request.get());  // Request takes ownership.

  BeginRequestInternal(request.Pass(), handler.Pass());
}

void ResourceDispatcherHostImpl::MarkAsTransferredNavigation(
    const GlobalRequestID& id) {
  GetLoader(id)->MarkAsTransferring();
}

void ResourceDispatcherHostImpl::CancelTransferringNavigation(
    const GlobalRequestID& id) {
  // Request should still exist and be in the middle of a transfer.
  DCHECK(IsTransferredNavigation(id));
  RemovePendingRequest(id.child_id, id.request_id);
}

void ResourceDispatcherHostImpl::ResumeDeferredNavigation(
    const GlobalRequestID& id) {
  ResourceLoader* loader = GetLoader(id);
  if (loader) {
    // The response we were meant to resume could have already been canceled.
    ResourceRequestInfoImpl* info = loader->GetRequestInfo();
    if (info->cross_site_handler())
      info->cross_site_handler()->ResumeResponse();
  }
}

// The object died, so cancel and detach all requests associated with it except
// for downloads and detachable resources, which belong to the browser process
// even if initiated via a renderer.
void ResourceDispatcherHostImpl::CancelRequestsForProcess(int child_id) {
  CancelRequestsForRoute(child_id, -1 /* cancel all */);
  registered_temp_files_.erase(child_id);
}

void ResourceDispatcherHostImpl::CancelRequestsForRoute(int child_id,
                                                        int route_id) {
  // Since pending_requests_ is a map, we first build up a list of all of the
  // matching requests to be cancelled, and then we cancel them.  Since there
  // may be more than one request to cancel, we cannot simply hold onto the map
  // iterators found in the first loop.

  // Find the global ID of all matching elements.
  bool any_requests_transferring = false;
  std::vector<GlobalRequestID> matching_requests;
  for (LoaderMap::const_iterator i = pending_loaders_.begin();
       i != pending_loaders_.end(); ++i) {
    if (i->first.child_id != child_id)
      continue;

    ResourceRequestInfoImpl* info = i->second->GetRequestInfo();

    GlobalRequestID id(child_id, i->first.request_id);
    DCHECK(id == i->first);
    // Don't cancel navigations that are expected to live beyond this process.
    if (IsTransferredNavigation(id))
      any_requests_transferring = true;
    if (info->detachable_handler()) {
      info->detachable_handler()->Detach();
    } else if (!info->IsDownload() && !info->is_stream() &&
               !IsTransferredNavigation(id) &&
               (route_id == -1 || route_id == info->GetRouteID())) {
      matching_requests.push_back(id);
    }
  }

  // Remove matches.
  for (size_t i = 0; i < matching_requests.size(); ++i) {
    LoaderMap::iterator iter = pending_loaders_.find(matching_requests[i]);
    // Although every matching request was in pending_requests_ when we built
    // matching_requests, it is normal for a matching request to be not found
    // in pending_requests_ after we have removed some matching requests from
    // pending_requests_.  For example, deleting a net::URLRequest that has
    // exclusive (write) access to an HTTP cache entry may unblock another
    // net::URLRequest that needs exclusive access to the same cache entry, and
    // that net::URLRequest may complete and remove itself from
    // pending_requests_. So we need to check that iter is not equal to
    // pending_requests_.end().
    if (iter != pending_loaders_.end())
      RemovePendingLoader(iter);
  }

  // Don't clear the blocked loaders or offline policy maps if any of the
  // requests in route_id are being transferred to a new process, since those
  // maps will be updated with the new route_id after the transfer.  Otherwise
  // we will lose track of this info when the old route goes away, before the
  // new one is created.
  if (any_requests_transferring)
    return;

  // Now deal with blocked requests if any.
  if (route_id != -1) {
    if (blocked_loaders_map_.find(GlobalRoutingID(child_id, route_id)) !=
        blocked_loaders_map_.end()) {
      CancelBlockedRequestsForRoute(child_id, route_id);
    }
  } else {
    // We have to do all render views for the process |child_id|.
    // Note that we have to do this in 2 passes as we cannot call
    // CancelBlockedRequestsForRoute while iterating over
    // blocked_loaders_map_, as it modifies it.
    std::set<int> route_ids;
    for (BlockedLoadersMap::const_iterator iter = blocked_loaders_map_.begin();
         iter != blocked_loaders_map_.end(); ++iter) {
      if (iter->first.child_id == child_id)
        route_ids.insert(iter->first.route_id);
    }
    for (std::set<int>::const_iterator iter = route_ids.begin();
        iter != route_ids.end(); ++iter) {
      CancelBlockedRequestsForRoute(child_id, *iter);
    }
  }

  // Cleanup the offline state for the route.
  if (-1 != route_id) {
    OfflineMap::iterator it = offline_policy_map_.find(
        GlobalRoutingID(child_id, route_id));
    if (offline_policy_map_.end() != it) {
      delete it->second;
      offline_policy_map_.erase(it);
    }
  } else {
    for (OfflineMap::iterator it = offline_policy_map_.begin();
         offline_policy_map_.end() != it;) {
      // Increment iterator so deletion doesn't invalidate it.
      OfflineMap::iterator current_it = it++;

      if (child_id == current_it->first.child_id) {
        delete current_it->second;
        offline_policy_map_.erase(current_it);
      }
    }
  }
}

// Cancels the request and removes it from the list.
void ResourceDispatcherHostImpl::RemovePendingRequest(int child_id,
                                                      int request_id) {
  LoaderMap::iterator i = pending_loaders_.find(
      GlobalRequestID(child_id, request_id));
  if (i == pending_loaders_.end()) {
    NOTREACHED() << "Trying to remove a request that's not here";
    return;
  }
  RemovePendingLoader(i);
}

void ResourceDispatcherHostImpl::RemovePendingLoader(
    const LoaderMap::iterator& iter) {
  ResourceRequestInfoImpl* info = iter->second->GetRequestInfo();

  // Remove the memory credit that we added when pushing the request onto
  // the pending list.
  IncrementOutstandingRequestsMemory(-1, *info);

  pending_loaders_.erase(iter);

  // If we have no more pending requests, then stop the load state monitor
  if (pending_loaders_.empty() && update_load_states_timer_)
    update_load_states_timer_->Stop();
}

void ResourceDispatcherHostImpl::CancelRequest(int child_id,
                                               int request_id) {
  ResourceLoader* loader = GetLoader(child_id, request_id);
  if (!loader) {
    // We probably want to remove this warning eventually, but I wanted to be
    // able to notice when this happens during initial development since it
    // should be rare and may indicate a bug.
    DVLOG(1) << "Canceling a request that wasn't found";
    return;
  }

  RemovePendingRequest(child_id, request_id);
}

ResourceDispatcherHostImpl::OustandingRequestsStats
ResourceDispatcherHostImpl::GetOutstandingRequestsStats(
    const ResourceRequestInfoImpl& info) {
  OutstandingRequestsStatsMap::iterator entry =
      outstanding_requests_stats_map_.find(info.GetChildID());
  OustandingRequestsStats stats = { 0, 0 };
  if (entry != outstanding_requests_stats_map_.end())
    stats = entry->second;
  return stats;
}

void ResourceDispatcherHostImpl::UpdateOutstandingRequestsStats(
    const ResourceRequestInfoImpl& info,
    const OustandingRequestsStats& stats) {
  if (stats.memory_cost == 0 && stats.num_requests == 0)
    outstanding_requests_stats_map_.erase(info.GetChildID());
  else
    outstanding_requests_stats_map_[info.GetChildID()] = stats;
}

ResourceDispatcherHostImpl::OustandingRequestsStats
ResourceDispatcherHostImpl::IncrementOutstandingRequestsMemory(
    int count,
    const ResourceRequestInfoImpl& info) {
  DCHECK_EQ(1, abs(count));

  // Retrieve the previous value (defaulting to 0 if not found).
  OustandingRequestsStats stats = GetOutstandingRequestsStats(info);

  // Insert/update the total; delete entries when their count reaches 0.
  stats.memory_cost += count * info.memory_cost();
  DCHECK_GE(stats.memory_cost, 0);
  UpdateOutstandingRequestsStats(info, stats);

  return stats;
}

ResourceDispatcherHostImpl::OustandingRequestsStats
ResourceDispatcherHostImpl::IncrementOutstandingRequestsCount(
    int count,
    const ResourceRequestInfoImpl& info) {
  DCHECK_EQ(1, abs(count));
  num_in_flight_requests_ += count;

  OustandingRequestsStats stats = GetOutstandingRequestsStats(info);
  stats.num_requests += count;
  DCHECK_GE(stats.num_requests, 0);
  UpdateOutstandingRequestsStats(info, stats);

  return stats;
}

bool ResourceDispatcherHostImpl::HasSufficientResourcesForRequest(
    const net::URLRequest* request_) {
  const ResourceRequestInfoImpl* info =
      ResourceRequestInfoImpl::ForRequest(request_);
  OustandingRequestsStats stats = IncrementOutstandingRequestsCount(1, *info);

  if (stats.num_requests > max_num_in_flight_requests_per_process_)
    return false;
  if (num_in_flight_requests_ > max_num_in_flight_requests_)
    return false;

  return true;
}

void ResourceDispatcherHostImpl::FinishedWithResourcesForRequest(
    const net::URLRequest* request_) {
  const ResourceRequestInfoImpl* info =
      ResourceRequestInfoImpl::ForRequest(request_);
  IncrementOutstandingRequestsCount(-1, *info);
}

// static
int ResourceDispatcherHostImpl::CalculateApproximateMemoryCost(
    net::URLRequest* request) {
  // The following fields should be a minor size contribution (experimentally
  // on the order of 100). However since they are variable length, it could
  // in theory be a sizeable contribution.
  int strings_cost = request->extra_request_headers().ToString().size() +
                     request->original_url().spec().size() +
                     request->referrer().size() +
                     request->method().size();

  // Note that this expression will typically be dominated by:
  // |kAvgBytesPerOutstandingRequest|.
  return kAvgBytesPerOutstandingRequest + strings_cost;
}

void ResourceDispatcherHostImpl::BeginRequestInternal(
    scoped_ptr<net::URLRequest> request,
    scoped_ptr<ResourceHandler> handler) {
  DCHECK(!request->is_pending());
  ResourceRequestInfoImpl* info =
      ResourceRequestInfoImpl::ForRequest(request.get());

  if ((TimeTicks::Now() - last_user_gesture_time_) <
      TimeDelta::FromMilliseconds(kUserGestureWindowMs)) {
    request->SetLoadFlags(
        request->load_flags() | net::LOAD_MAYBE_USER_GESTURE);
  }

  // Add the memory estimate that starting this request will consume.
  info->set_memory_cost(CalculateApproximateMemoryCost(request.get()));

  // If enqueing/starting this request will exceed our per-process memory
  // bound, abort it right away.
  OustandingRequestsStats stats = IncrementOutstandingRequestsMemory(1, *info);
  if (stats.memory_cost > max_outstanding_requests_cost_per_process_) {
    // We call "CancelWithError()" as a way of setting the net::URLRequest's
    // status -- it has no effect beyond this, since the request hasn't started.
    request->CancelWithError(net::ERR_INSUFFICIENT_RESOURCES);

    bool defer = false;
    handler->OnResponseCompleted(info->GetRequestID(), request->status(),
                                 std::string(), &defer);
    if (defer) {
      // TODO(darin): The handler is not ready for us to kill the request. Oops!
      NOTREACHED();
    }

    IncrementOutstandingRequestsMemory(-1, *info);

    // A ResourceHandler must not outlive its associated URLRequest.
    handler.reset();
    return;
  }

  linked_ptr<ResourceLoader> loader(
      new ResourceLoader(request.Pass(), handler.Pass(), this));

  GlobalRoutingID id(info->GetGlobalRoutingID());
  BlockedLoadersMap::const_iterator iter = blocked_loaders_map_.find(id);
  if (iter != blocked_loaders_map_.end()) {
    // The request should be blocked.
    iter->second->push_back(loader);
    return;
  }

  StartLoading(info, loader);
}

void ResourceDispatcherHostImpl::StartLoading(
    ResourceRequestInfoImpl* info,
    const linked_ptr<ResourceLoader>& loader) {
  pending_loaders_[info->GetGlobalRequestID()] = loader;

  loader->StartRequest();
}

void ResourceDispatcherHostImpl::OnUserGesture(WebContentsImpl* contents) {
  last_user_gesture_time_ = TimeTicks::Now();
}

net::URLRequest* ResourceDispatcherHostImpl::GetURLRequest(
    const GlobalRequestID& id) {
  ResourceLoader* loader = GetLoader(id);
  if (!loader)
    return NULL;

  return loader->request();
}

namespace {

// This function attempts to return the "more interesting" load state of |a|
// and |b|.  We don't have temporal information about these load states
// (meaning we don't know when we transitioned into these states), so we just
// rank them according to how "interesting" the states are.
//
// We take advantage of the fact that the load states are an enumeration listed
// in the order in which they occur during the lifetime of a request, so we can
// regard states with larger numeric values as being further along toward
// completion.  We regard those states as more interesting to report since they
// represent progress.
//
// For example, by this measure "tranferring data" is a more interesting state
// than "resolving host" because when we are transferring data we are actually
// doing something that corresponds to changes that the user might observe,
// whereas waiting for a host name to resolve implies being stuck.
//
const net::LoadStateWithParam& MoreInterestingLoadState(
    const net::LoadStateWithParam& a, const net::LoadStateWithParam& b) {
  return (a.state < b.state) ? b : a;
}

// Carries information about a load state change.
struct LoadInfo {
  GURL url;
  net::LoadStateWithParam load_state;
  uint64 upload_position;
  uint64 upload_size;
};

// Map from ProcessID+RouteID pair to LoadState
typedef std::map<GlobalRoutingID, LoadInfo> LoadInfoMap;

// Used to marshal calls to LoadStateChanged from the IO to UI threads.  We do
// them all as a single callback to avoid spamming the UI thread.
void LoadInfoUpdateCallback(const LoadInfoMap& info_map) {
  LoadInfoMap::const_iterator i;
  for (i = info_map.begin(); i != info_map.end(); ++i) {
    RenderViewHostImpl* view =
        RenderViewHostImpl::FromID(i->first.child_id, i->first.route_id);
    if (view)  // The view could be gone at this point.
      view->LoadStateChanged(i->second.url, i->second.load_state,
                             i->second.upload_position,
                             i->second.upload_size);
  }
}

}  // namespace

void ResourceDispatcherHostImpl::UpdateLoadStates() {
  // Populate this map with load state changes, and then send them on to the UI
  // thread where they can be passed along to the respective RVHs.
  LoadInfoMap info_map;

  LoaderMap::const_iterator i;

  // Determine the largest upload size of all requests
  // in each View (good chance it's zero).
  std::map<GlobalRoutingID, uint64> largest_upload_size;
  for (i = pending_loaders_.begin(); i != pending_loaders_.end(); ++i) {
    net::URLRequest* request = i->second->request();
    ResourceRequestInfoImpl* info = i->second->GetRequestInfo();
    uint64 upload_size = request->GetUploadProgress().size();
    if (request->GetLoadState().state != net::LOAD_STATE_SENDING_REQUEST)
      upload_size = 0;
    GlobalRoutingID id(info->GetGlobalRoutingID());
    if (upload_size && largest_upload_size[id] < upload_size)
      largest_upload_size[id] = upload_size;
  }

  for (i = pending_loaders_.begin(); i != pending_loaders_.end(); ++i) {
    net::URLRequest* request = i->second->request();
    ResourceRequestInfoImpl* info = i->second->GetRequestInfo();
    net::LoadStateWithParam load_state = request->GetLoadState();
    net::UploadProgress progress = request->GetUploadProgress();

    // We also poll for upload progress on this timer and send upload
    // progress ipc messages to the plugin process.
    i->second->ReportUploadProgress();

    GlobalRoutingID id(info->GetGlobalRoutingID());

    // If a request is uploading data, ignore all other requests so that the
    // upload progress takes priority for being shown in the status bar.
    if (largest_upload_size.find(id) != largest_upload_size.end() &&
        progress.size() < largest_upload_size[id])
      continue;

    net::LoadStateWithParam to_insert = load_state;
    LoadInfoMap::iterator existing = info_map.find(id);
    if (existing != info_map.end()) {
      to_insert =
          MoreInterestingLoadState(existing->second.load_state, load_state);
      if (to_insert.state == existing->second.load_state.state)
        continue;
    }
    LoadInfo& load_info = info_map[id];
    load_info.url = request->url();
    load_info.load_state = to_insert;
    load_info.upload_size = progress.size();
    load_info.upload_position = progress.position();
  }

  if (info_map.empty())
    return;

  BrowserThread::PostTask(
      BrowserThread::UI, FROM_HERE,
      base::Bind(&LoadInfoUpdateCallback, info_map));
}

void ResourceDispatcherHostImpl::BlockRequestsForRoute(int child_id,
                                                       int route_id) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
  GlobalRoutingID key(child_id, route_id);
  DCHECK(blocked_loaders_map_.find(key) == blocked_loaders_map_.end()) <<
      "BlockRequestsForRoute called  multiple time for the same RVH";
  blocked_loaders_map_[key] = new BlockedLoadersList();
}

void ResourceDispatcherHostImpl::ResumeBlockedRequestsForRoute(int child_id,
                                                               int route_id) {
  ProcessBlockedRequestsForRoute(child_id, route_id, false);
}

void ResourceDispatcherHostImpl::CancelBlockedRequestsForRoute(int child_id,
                                                               int route_id) {
  ProcessBlockedRequestsForRoute(child_id, route_id, true);
}

void ResourceDispatcherHostImpl::ProcessBlockedRequestsForRoute(
    int child_id,
    int route_id,
    bool cancel_requests) {
  BlockedLoadersMap::iterator iter = blocked_loaders_map_.find(
      GlobalRoutingID(child_id, route_id));
  if (iter == blocked_loaders_map_.end()) {
    // It's possible to reach here if the renderer crashed while an interstitial
    // page was showing.
    return;
  }

  BlockedLoadersList* loaders = iter->second;

  // Removing the vector from the map unblocks any subsequent requests.
  blocked_loaders_map_.erase(iter);

  for (BlockedLoadersList::iterator loaders_iter = loaders->begin();
       loaders_iter != loaders->end(); ++loaders_iter) {
    linked_ptr<ResourceLoader> loader = *loaders_iter;
    ResourceRequestInfoImpl* info = loader->GetRequestInfo();
    if (cancel_requests) {
      IncrementOutstandingRequestsMemory(-1, *info);
    } else {
      StartLoading(info, loader);
    }
  }

  delete loaders;
}

ResourceDispatcherHostImpl::HttpAuthRelationType
ResourceDispatcherHostImpl::HttpAuthRelationTypeOf(
    const GURL& request_url,
    const GURL& first_party) {
  if (!first_party.is_valid())
    return HTTP_AUTH_RELATION_TOP;

  if (net::registry_controlled_domains::SameDomainOrHost(
          first_party, request_url,
          net::registry_controlled_domains::INCLUDE_PRIVATE_REGISTRIES))
    return HTTP_AUTH_RELATION_SAME_DOMAIN;

  if (allow_cross_origin_auth_prompt())
    return HTTP_AUTH_RELATION_ALLOWED_CROSS;

  return HTTP_AUTH_RELATION_BLOCKED_CROSS;
}

bool ResourceDispatcherHostImpl::allow_cross_origin_auth_prompt() {
  return allow_cross_origin_auth_prompt_;
}

bool ResourceDispatcherHostImpl::IsTransferredNavigation(
    const GlobalRequestID& id) const {
  ResourceLoader* loader = GetLoader(id);
  return loader ? loader->is_transferring() : false;
}

ResourceLoader* ResourceDispatcherHostImpl::GetLoader(
    const GlobalRequestID& id) const {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));

  LoaderMap::const_iterator i = pending_loaders_.find(id);
  if (i == pending_loaders_.end())
    return NULL;

  return i->second.get();
}

ResourceLoader* ResourceDispatcherHostImpl::GetLoader(int child_id,
                                                      int request_id) const {
  return GetLoader(GlobalRequestID(child_id, request_id));
}

void ResourceDispatcherHostImpl::RegisterResourceMessageDelegate(
    const GlobalRequestID& id, ResourceMessageDelegate* delegate) {
  DelegateMap::iterator it = delegate_map_.find(id);
  if (it == delegate_map_.end()) {
    it = delegate_map_.insert(
        std::make_pair(id, new ObserverList<ResourceMessageDelegate>)).first;
  }
  it->second->AddObserver(delegate);
}

void ResourceDispatcherHostImpl::UnregisterResourceMessageDelegate(
    const GlobalRequestID& id, ResourceMessageDelegate* delegate) {
  DCHECK(ContainsKey(delegate_map_, id));
  DelegateMap::iterator it = delegate_map_.find(id);
  DCHECK(it->second->HasObserver(delegate));
  it->second->RemoveObserver(delegate);
  if (!it->second->might_have_observers()) {
    delete it->second;
    delegate_map_.erase(it);
  }
}

int ResourceDispatcherHostImpl::BuildLoadFlagsForRequest(
    const ResourceHostMsg_Request& request_data,
    int child_id,
    bool is_sync_load) {
  int load_flags = request_data.load_flags;

  // Although EV status is irrelevant to sub-frames and sub-resources, we have
  // to perform EV certificate verification on all resources because an HTTP
  // keep-alive connection created to load a sub-frame or a sub-resource could
  // be reused to load a main frame.
  load_flags |= net::LOAD_VERIFY_EV_CERT;
  if (request_data.resource_type == ResourceType::MAIN_FRAME) {
    load_flags |= net::LOAD_MAIN_FRAME;
  } else if (request_data.resource_type == ResourceType::SUB_FRAME) {
    load_flags |= net::LOAD_SUB_FRAME;
  } else if (request_data.resource_type == ResourceType::PREFETCH) {
    load_flags |= (net::LOAD_PREFETCH | net::LOAD_DO_NOT_PROMPT_FOR_LOGIN);
  } else if (request_data.resource_type == ResourceType::FAVICON) {
    load_flags |= net::LOAD_DO_NOT_PROMPT_FOR_LOGIN;
  } else if (request_data.resource_type == ResourceType::IMAGE) {
    // Prevent third-party image content from prompting for login, as this
    // is often a scam to extract credentials for another domain from the user.
    // Only block image loads, as the attack applies largely to the "src"
    // property of the <img> tag. It is common for web properties to allow
    // untrusted values for <img src>; this is considered a fair thing for an
    // HTML sanitizer to do. Conversely, any HTML sanitizer that didn't
    // filter sources for <script>, <link>, <embed>, <object>, <iframe> tags
    // would be considered vulnerable in and of itself.
    HttpAuthRelationType relation_type = HttpAuthRelationTypeOf(
        request_data.url, request_data.first_party_for_cookies);
    if (relation_type == HTTP_AUTH_RELATION_BLOCKED_CROSS) {
      load_flags |= (net::LOAD_DO_NOT_USE_EMBEDDED_IDENTITY |
                     net::LOAD_DO_NOT_PROMPT_FOR_LOGIN);
    }
  }

  if (is_sync_load)
    load_flags |= net::LOAD_IGNORE_LIMITS;

  ChildProcessSecurityPolicyImpl* policy =
      ChildProcessSecurityPolicyImpl::GetInstance();
  if (!policy->CanSendCookiesForOrigin(child_id, request_data.url)) {
    load_flags |= (net::LOAD_DO_NOT_SEND_COOKIES |
                   net::LOAD_DO_NOT_SEND_AUTH_DATA |
                   net::LOAD_DO_NOT_SAVE_COOKIES);
  }

  // Raw headers are sensitive, as they include Cookie/Set-Cookie, so only
  // allow requesting them if requester has ReadRawCookies permission.
  if ((load_flags & net::LOAD_REPORT_RAW_HEADERS)
      && !policy->CanReadRawCookies(child_id)) {
    VLOG(1) << "Denied unauthorized request for raw headers";
    load_flags &= ~net::LOAD_REPORT_RAW_HEADERS;
  }

  return load_flags;
}

}  // namespace content