root/cc/scheduler/scheduler_state_machine_unittest.cc

DEFINITIONS

1. CreateAndInitializeOutputSurfaceWithActivatedCommit
2. SetCommitState
3. ForcedRedrawState
4. SetBeginImplFrameState
5. begin_impl_frame_state
6. output_surface_state
7. SetReadbackState
8. readback_state
9. NeedsCommit
10. SetNeedsRedraw
11. SetNeedsForcedRedrawForTimeout
12. NeedsForcedRedrawForTimeout
13. SetNeedsForcedRedrawForReadback
14. NeedsForcedRedrawForReadback
15. SetActiveTreeNeedsFirstDraw
16. CanDraw
17. Visible
18. PendingActivationsShouldBeForced
19. SetHasPendingTree
20. TEST
21. TEST
22. TEST
23. TEST
24. TEST
25. TEST
26. TestFailedDrawsEventuallyForceDrawAfterNextCommit
27. TEST
28. TEST
29. TEST
30. TEST
31. TEST
32. TEST
33. TEST
34. TEST
35. TEST
36. TestSetNeedsCommitIsNotLost
37. TEST
38. TEST
39. TEST
40. TEST
41. TEST
42. TEST
43. TEST
44. TEST
45. TEST
46. TEST
47. TEST
48. TEST
49. TEST
50. TEST
51. TEST
52. TEST
53. TEST
54. TEST
55. TEST
56. TEST
57. TestForceCommitWhenReplacementActivationInProgress
58. TEST
59. TEST
60. TEST
61. TEST
62. TEST
63. TEST
64. TEST
65. TEST
66. TEST
67. TEST
68. TEST
69. TEST
70. TEST

// Copyright 2011 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 "cc/scheduler/scheduler_state_machine.h"

#include "cc/scheduler/scheduler.h"
#include "testing/gtest/include/gtest/gtest.h"

#define EXPECT_ACTION_UPDATE_STATE(action)                                   \
  EXPECT_EQ(action, state.NextAction()) << *state.AsValue();                 \
  if (action == SchedulerStateMachine::ACTION_DRAW_AND_SWAP_IF_POSSIBLE ||   \
      action == SchedulerStateMachine::ACTION_DRAW_AND_SWAP_FORCED) {        \
    EXPECT_EQ(SchedulerStateMachine::BEGIN_IMPL_FRAME_STATE_INSIDE_DEADLINE, \
              state.begin_impl_frame_state())                                \
        << *state.AsValue();                                                 \
  }                                                                          \
  state.UpdateState(action);                                                 \
  if (action == SchedulerStateMachine::ACTION_NONE) {                        \
    if (state.begin_impl_frame_state() ==                                    \
        SchedulerStateMachine::BEGIN_IMPL_FRAME_STATE_BEGIN_FRAME_STARTING)  \
      state.OnBeginImplFrameDeadlinePending();                               \
    if (state.begin_impl_frame_state() ==                                    \
        SchedulerStateMachine::BEGIN_IMPL_FRAME_STATE_INSIDE_DEADLINE)       \
      state.OnBeginImplFrameIdle();                                          \
  }

namespace cc {

namespace {

const SchedulerStateMachine::BeginImplFrameState all_begin_impl_frame_states[] =
    {SchedulerStateMachine::BEGIN_IMPL_FRAME_STATE_IDLE,
     SchedulerStateMachine::BEGIN_IMPL_FRAME_STATE_BEGIN_FRAME_STARTING,
     SchedulerStateMachine::BEGIN_IMPL_FRAME_STATE_INSIDE_BEGIN_FRAME,
     SchedulerStateMachine::BEGIN_IMPL_FRAME_STATE_INSIDE_DEADLINE, };

const SchedulerStateMachine::CommitState all_commit_states[] = {
    SchedulerStateMachine::COMMIT_STATE_IDLE,
    SchedulerStateMachine::COMMIT_STATE_BEGIN_MAIN_FRAME_SENT,
    SchedulerStateMachine::COMMIT_STATE_BEGIN_MAIN_FRAME_STARTED,
    SchedulerStateMachine::COMMIT_STATE_READY_TO_COMMIT,
    SchedulerStateMachine::COMMIT_STATE_WAITING_FOR_ACTIVATION,
    SchedulerStateMachine::COMMIT_STATE_WAITING_FOR_FIRST_DRAW};

// Exposes the protected state fields of the SchedulerStateMachine for testing
class StateMachine : public SchedulerStateMachine {
 public:
  explicit StateMachine(const SchedulerSettings& scheduler_settings)
      : SchedulerStateMachine(scheduler_settings) {}

  void CreateAndInitializeOutputSurfaceWithActivatedCommit() {
    DidCreateAndInitializeOutputSurface();
    output_surface_state_ = OUTPUT_SURFACE_ACTIVE;
  }

  void SetCommitState(CommitState cs) { commit_state_ = cs; }
  CommitState CommitState() const { return commit_state_; }

  ForcedRedrawOnTimeoutState ForcedRedrawState() const {
    return forced_redraw_state_;
  }

  void SetBeginImplFrameState(BeginImplFrameState bifs) {
    begin_impl_frame_state_ = bifs;
  }

  BeginImplFrameState begin_impl_frame_state() const {
    return begin_impl_frame_state_;
  }

  OutputSurfaceState output_surface_state() const {
    return output_surface_state_;
  }

  void SetReadbackState(SynchronousReadbackState rs) { readback_state_ = rs; }
  SynchronousReadbackState readback_state() const { return readback_state_; }

  bool NeedsCommit() const { return needs_commit_; }

  void SetNeedsRedraw(bool b) { needs_redraw_ = b; }

  void SetNeedsForcedRedrawForTimeout(bool b) {
    forced_redraw_state_ = FORCED_REDRAW_STATE_WAITING_FOR_COMMIT;
    active_tree_needs_first_draw_ = true;
  }
  bool NeedsForcedRedrawForTimeout() const {
    return forced_redraw_state_ != FORCED_REDRAW_STATE_IDLE;
  }

  void SetNeedsForcedRedrawForReadback() {
    readback_state_ = READBACK_STATE_WAITING_FOR_DRAW_AND_READBACK;
    active_tree_needs_first_draw_ = true;
  }

  bool NeedsForcedRedrawForReadback() const {
    return readback_state_ != READBACK_STATE_IDLE;
  }

  void SetActiveTreeNeedsFirstDraw(bool needs_first_draw) {
    active_tree_needs_first_draw_ = needs_first_draw;
  }

  bool CanDraw() const { return can_draw_; }
  bool Visible() const { return visible_; }

  bool PendingActivationsShouldBeForced() const {
    return SchedulerStateMachine::PendingActivationsShouldBeForced();
  }

  void SetHasPendingTree(bool has_pending_tree) {
    has_pending_tree_ = has_pending_tree;
  }
};

TEST(SchedulerStateMachineTest, TestNextActionBeginsMainFrameIfNeeded) {
  SchedulerSettings default_scheduler_settings;

  // If no commit needed, do nothing.
  {
    StateMachine state(default_scheduler_settings);
    state.SetCanStart();
    EXPECT_ACTION_UPDATE_STATE(
        SchedulerStateMachine::ACTION_BEGIN_OUTPUT_SURFACE_CREATION)
    state.CreateAndInitializeOutputSurfaceWithActivatedCommit();
    state.SetCommitState(SchedulerStateMachine::COMMIT_STATE_IDLE);
    state.SetNeedsRedraw(false);
    state.SetVisible(true);

    EXPECT_FALSE(state.BeginImplFrameNeeded());

    EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
    EXPECT_FALSE(state.BeginImplFrameNeeded());
    state.OnBeginImplFrame(BeginFrameArgs::CreateForTesting());

    EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
    state.OnBeginImplFrameDeadline();
  }

  // If commit requested but can_start is still false, do nothing.
  {
    StateMachine state(default_scheduler_settings);
    state.SetCommitState(SchedulerStateMachine::COMMIT_STATE_IDLE);
    state.SetNeedsRedraw(false);
    state.SetVisible(true);
    state.SetNeedsCommit();

    EXPECT_FALSE(state.BeginImplFrameNeeded());

    EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
    EXPECT_FALSE(state.BeginImplFrameNeeded());
    state.OnBeginImplFrame(BeginFrameArgs::CreateForTesting());
    EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
    state.OnBeginImplFrameDeadline();
  }

  // If commit requested, begin a main frame.
  {
    StateMachine state(default_scheduler_settings);
    state.SetCommitState(SchedulerStateMachine::COMMIT_STATE_IDLE);
    state.SetCanStart();
    state.UpdateState(state.NextAction());
    state.CreateAndInitializeOutputSurfaceWithActivatedCommit();
    state.SetNeedsRedraw(false);
    state.SetVisible(true);
    state.SetNeedsCommit();

    EXPECT_TRUE(state.BeginImplFrameNeeded());

    state.OnBeginImplFrame(BeginFrameArgs::CreateForTesting());
    EXPECT_ACTION_UPDATE_STATE(
        SchedulerStateMachine::ACTION_SEND_BEGIN_MAIN_FRAME);
  }

  // Begin the frame, make sure needs_commit and commit_state update correctly.
  {
    StateMachine state(default_scheduler_settings);
    state.SetCanStart();
    state.UpdateState(state.NextAction());
    state.CreateAndInitializeOutputSurfaceWithActivatedCommit();
    state.SetVisible(true);
    state.UpdateState(SchedulerStateMachine::ACTION_SEND_BEGIN_MAIN_FRAME);
    EXPECT_EQ(SchedulerStateMachine::COMMIT_STATE_BEGIN_MAIN_FRAME_SENT,
              state.CommitState());
    EXPECT_FALSE(state.NeedsCommit());
  }
}

// Explicitly test main_frame_before_draw_enabled = false
TEST(SchedulerStateMachineTest, MainFrameBeforeDrawDisabled) {
  SchedulerSettings scheduler_settings;
  scheduler_settings.impl_side_painting = true;
  scheduler_settings.main_frame_before_draw_enabled = false;
  StateMachine state(scheduler_settings);
  state.SetCommitState(SchedulerStateMachine::COMMIT_STATE_IDLE);
  state.SetCanStart();
  state.UpdateState(state.NextAction());
  state.CreateAndInitializeOutputSurfaceWithActivatedCommit();
  state.SetNeedsRedraw(false);
  state.SetVisible(true);
  state.SetCanDraw(true);
  state.SetNeedsCommit();

  EXPECT_TRUE(state.BeginImplFrameNeeded());

  // Commit to the pending tree.
  state.OnBeginImplFrame(BeginFrameArgs::CreateForTesting());
  EXPECT_ACTION_UPDATE_STATE(
      SchedulerStateMachine::ACTION_SEND_BEGIN_MAIN_FRAME);
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
  state.NotifyBeginMainFrameStarted();
  state.NotifyReadyToCommit();
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_COMMIT);
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
  EXPECT_EQ(state.CommitState(),
            SchedulerStateMachine::COMMIT_STATE_WAITING_FOR_FIRST_DRAW);

  state.OnBeginImplFrameDeadline();
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
  EXPECT_EQ(state.CommitState(),
            SchedulerStateMachine::COMMIT_STATE_WAITING_FOR_FIRST_DRAW);

  // Verify that the next commit doesn't start until the previous
  // commit has been drawn.
  state.SetNeedsCommit();
  state.OnBeginImplFrame(BeginFrameArgs::CreateForTesting());
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);

  // Verify NotifyReadyToActivate unblocks activation, draw, and
  // commit in that order.
  state.NotifyReadyToActivate();
  EXPECT_ACTION_UPDATE_STATE(
      SchedulerStateMachine::ACTION_ACTIVATE_PENDING_TREE);
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
  EXPECT_EQ(state.CommitState(),
            SchedulerStateMachine::COMMIT_STATE_WAITING_FOR_FIRST_DRAW);

  EXPECT_TRUE(state.ShouldTriggerBeginImplFrameDeadlineEarly());
  state.OnBeginImplFrameDeadline();
  EXPECT_ACTION_UPDATE_STATE(
      SchedulerStateMachine::ACTION_DRAW_AND_SWAP_IF_POSSIBLE);
  EXPECT_EQ(state.CommitState(), SchedulerStateMachine::COMMIT_STATE_IDLE);
  EXPECT_ACTION_UPDATE_STATE(
      SchedulerStateMachine::ACTION_SEND_BEGIN_MAIN_FRAME);
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
  EXPECT_EQ(state.CommitState(),
            SchedulerStateMachine::COMMIT_STATE_BEGIN_MAIN_FRAME_SENT);

  state.NotifyBeginMainFrameStarted();
  state.NotifyReadyToCommit();
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_COMMIT);
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
  EXPECT_EQ(state.CommitState(),
            SchedulerStateMachine::COMMIT_STATE_WAITING_FOR_FIRST_DRAW);
}

// Explicitly test main_frame_before_activation_enabled = true
TEST(SchedulerStateMachineTest, MainFrameBeforeActivationEnabled) {
  SchedulerSettings scheduler_settings;
  scheduler_settings.impl_side_painting = true;
  scheduler_settings.main_frame_before_activation_enabled = true;
  StateMachine state(scheduler_settings);
  state.SetCommitState(SchedulerStateMachine::COMMIT_STATE_IDLE);
  state.SetCanStart();
  state.UpdateState(state.NextAction());
  state.CreateAndInitializeOutputSurfaceWithActivatedCommit();
  state.SetNeedsRedraw(false);
  state.SetVisible(true);
  state.SetCanDraw(true);
  state.SetNeedsCommit();

  EXPECT_TRUE(state.BeginImplFrameNeeded());

  // Commit to the pending tree.
  state.OnBeginImplFrame(BeginFrameArgs::CreateForTesting());
  EXPECT_ACTION_UPDATE_STATE(
      SchedulerStateMachine::ACTION_SEND_BEGIN_MAIN_FRAME);
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);

  state.NotifyBeginMainFrameStarted();
  state.NotifyReadyToCommit();
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_COMMIT);
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
  EXPECT_EQ(state.CommitState(), SchedulerStateMachine::COMMIT_STATE_IDLE);

  state.OnBeginImplFrameDeadline();
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);

  // Verify that the next commit starts while there is still a pending tree.
  state.SetNeedsCommit();
  state.OnBeginImplFrame(BeginFrameArgs::CreateForTesting());
  EXPECT_ACTION_UPDATE_STATE(
      SchedulerStateMachine::ACTION_SEND_BEGIN_MAIN_FRAME);
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);

  // Verify the pending commit doesn't overwrite the pending
  // tree until the pending tree has been activated.
  state.NotifyBeginMainFrameStarted();
  state.NotifyReadyToCommit();
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);

  // Verify NotifyReadyToActivate unblocks activation, draw, and
  // commit in that order.
  state.NotifyReadyToActivate();
  EXPECT_ACTION_UPDATE_STATE(
      SchedulerStateMachine::ACTION_ACTIVATE_PENDING_TREE);
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);

  EXPECT_TRUE(state.ShouldTriggerBeginImplFrameDeadlineEarly());
  state.OnBeginImplFrameDeadline();
  EXPECT_ACTION_UPDATE_STATE(
      SchedulerStateMachine::ACTION_DRAW_AND_SWAP_IF_POSSIBLE);
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_COMMIT);
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
  EXPECT_EQ(state.CommitState(), SchedulerStateMachine::COMMIT_STATE_IDLE);
}

TEST(SchedulerStateMachineTest,
     TestFailedDrawForAnimationCheckerboardSetsNeedsCommitAndDoesNotDrawAgain) {
  SchedulerSettings default_scheduler_settings;
  StateMachine state(default_scheduler_settings);
  state.SetCanStart();
  state.UpdateState(state.NextAction());
  state.CreateAndInitializeOutputSurfaceWithActivatedCommit();
  state.SetVisible(true);
  state.SetCanDraw(true);
  state.SetNeedsRedraw(true);
  EXPECT_TRUE(state.RedrawPending());
  EXPECT_TRUE(state.BeginImplFrameNeeded());
  state.OnBeginImplFrame(BeginFrameArgs::CreateForTesting());
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
  state.OnBeginImplFrameDeadline();

  // We're drawing now.
  EXPECT_ACTION_UPDATE_STATE(
      SchedulerStateMachine::ACTION_DRAW_AND_SWAP_IF_POSSIBLE);
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);

  EXPECT_FALSE(state.RedrawPending());
  EXPECT_FALSE(state.CommitPending());

  // Failing the draw makes us require a commit.
  state.DidDrawIfPossibleCompleted(
      DrawSwapReadbackResult::DRAW_ABORTED_CHECKERBOARD_ANIMATIONS);
  state.OnBeginImplFrame(BeginFrameArgs::CreateForTesting());
  EXPECT_ACTION_UPDATE_STATE(
      SchedulerStateMachine::ACTION_SEND_BEGIN_MAIN_FRAME);
  EXPECT_TRUE(state.RedrawPending());
  EXPECT_TRUE(state.CommitPending());
}

TEST(SchedulerStateMachineTest, TestFailedDrawForMissingHighResNeedsCommit) {
  SchedulerSettings default_scheduler_settings;
  StateMachine state(default_scheduler_settings);
  state.SetCanStart();
  state.UpdateState(state.NextAction());
  state.CreateAndInitializeOutputSurfaceWithActivatedCommit();
  state.SetVisible(true);
  state.SetCanDraw(true);
  state.SetNeedsRedraw(true);
  EXPECT_TRUE(state.RedrawPending());
  EXPECT_TRUE(state.BeginImplFrameNeeded());

  state.OnBeginImplFrame(BeginFrameArgs::CreateForTesting());
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
  state.OnBeginImplFrameDeadline();
  EXPECT_ACTION_UPDATE_STATE(
      SchedulerStateMachine::ACTION_DRAW_AND_SWAP_IF_POSSIBLE);
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
  EXPECT_FALSE(state.RedrawPending());
  EXPECT_FALSE(state.CommitPending());

  // Missing high res content requires a commit (but not a redraw)
  state.DidDrawIfPossibleCompleted(
      DrawSwapReadbackResult::DRAW_ABORTED_MISSING_HIGH_RES_CONTENT);
  state.OnBeginImplFrame(BeginFrameArgs::CreateForTesting());
  EXPECT_ACTION_UPDATE_STATE(
      SchedulerStateMachine::ACTION_SEND_BEGIN_MAIN_FRAME);
  EXPECT_FALSE(state.RedrawPending());
  EXPECT_TRUE(state.CommitPending());
}

TEST(SchedulerStateMachineTest,
     TestsetNeedsRedrawDuringFailedDrawDoesNotRemoveNeedsRedraw) {
  SchedulerSettings default_scheduler_settings;
  StateMachine state(default_scheduler_settings);
  state.SetCanStart();
  state.UpdateState(state.NextAction());
  state.CreateAndInitializeOutputSurfaceWithActivatedCommit();

  state.SetVisible(true);
  state.SetCanDraw(true);
  state.SetNeedsRedraw(true);
  EXPECT_TRUE(state.RedrawPending());
  EXPECT_TRUE(state.BeginImplFrameNeeded());
  state.OnBeginImplFrame(BeginFrameArgs::CreateForTesting());
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
  state.OnBeginImplFrameDeadline();

  // We're drawing now.
  EXPECT_ACTION_UPDATE_STATE(
      SchedulerStateMachine::ACTION_DRAW_AND_SWAP_IF_POSSIBLE);
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
  EXPECT_FALSE(state.RedrawPending());
  EXPECT_FALSE(state.CommitPending());

  // While still in the same BeginMainFrame callback on the main thread,
  // set needs redraw again. This should not redraw.
  state.SetNeedsRedraw(true);
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);

  // Failing the draw for animation checkerboards makes us require a commit.
  state.DidDrawIfPossibleCompleted(
      DrawSwapReadbackResult::DRAW_ABORTED_CHECKERBOARD_ANIMATIONS);
  state.OnBeginImplFrame(BeginFrameArgs::CreateForTesting());
  EXPECT_ACTION_UPDATE_STATE(
      SchedulerStateMachine::ACTION_SEND_BEGIN_MAIN_FRAME);
  EXPECT_TRUE(state.RedrawPending());
}

void TestFailedDrawsEventuallyForceDrawAfterNextCommit(
    bool main_frame_before_draw_enabled) {
  SchedulerSettings scheduler_settings;
  scheduler_settings.main_frame_before_draw_enabled =
      main_frame_before_draw_enabled;
  scheduler_settings.maximum_number_of_failed_draws_before_draw_is_forced_ = 1;
  StateMachine state(scheduler_settings);
  state.SetCanStart();
  state.UpdateState(state.NextAction());
  state.CreateAndInitializeOutputSurfaceWithActivatedCommit();
  state.SetVisible(true);
  state.SetCanDraw(true);

  // Start a commit.
  state.SetNeedsCommit();
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
  state.OnBeginImplFrame(BeginFrameArgs::CreateForTesting());
  EXPECT_ACTION_UPDATE_STATE(
      SchedulerStateMachine::ACTION_SEND_BEGIN_MAIN_FRAME);
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
  EXPECT_TRUE(state.CommitPending());

  // Then initiate a draw.
  state.SetNeedsRedraw(true);
  state.OnBeginImplFrameDeadline();
  EXPECT_ACTION_UPDATE_STATE(
      SchedulerStateMachine::ACTION_DRAW_AND_SWAP_IF_POSSIBLE);

  // Fail the draw.
  state.DidDrawIfPossibleCompleted(
      DrawSwapReadbackResult::DRAW_ABORTED_CHECKERBOARD_ANIMATIONS);
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
  EXPECT_TRUE(state.BeginImplFrameNeeded());
  EXPECT_TRUE(state.RedrawPending());
  // But the commit is ongoing.
  EXPECT_TRUE(state.CommitPending());

  // Finish the commit. Note, we should not yet be forcing a draw, but should
  // continue the commit as usual.
  state.NotifyBeginMainFrameStarted();
  state.NotifyReadyToCommit();
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_COMMIT);
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
  EXPECT_TRUE(state.RedrawPending());

  // The redraw should be forced at the end of the next BeginImplFrame.
  state.OnBeginImplFrame(BeginFrameArgs::CreateForTesting());
  if (main_frame_before_draw_enabled) {
    EXPECT_ACTION_UPDATE_STATE(
        SchedulerStateMachine::ACTION_SEND_BEGIN_MAIN_FRAME);
  }
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
  state.OnBeginImplFrameDeadline();
  EXPECT_ACTION_UPDATE_STATE(
      SchedulerStateMachine::ACTION_DRAW_AND_SWAP_FORCED);
}

TEST(SchedulerStateMachineTest,
     TestFailedDrawsEventuallyForceDrawAfterNextCommit) {
  bool main_frame_before_draw_enabled = false;
  TestFailedDrawsEventuallyForceDrawAfterNextCommit(
      main_frame_before_draw_enabled);
}

TEST(SchedulerStateMachineTest,
     TestFailedDrawsEventuallyForceDrawAfterNextCommit_CommitBeforeDraw) {
  bool main_frame_before_draw_enabled = true;
  TestFailedDrawsEventuallyForceDrawAfterNextCommit(
      main_frame_before_draw_enabled);
}

TEST(SchedulerStateMachineTest, TestFailedDrawsDoNotRestartForcedDraw) {
  SchedulerSettings scheduler_settings;
  int draw_limit = 1;
  scheduler_settings.maximum_number_of_failed_draws_before_draw_is_forced_ =
      draw_limit;
  scheduler_settings.impl_side_painting = true;
  StateMachine state(scheduler_settings);
  state.SetCanStart();
  state.UpdateState(state.NextAction());
  state.CreateAndInitializeOutputSurfaceWithActivatedCommit();
  state.SetVisible(true);
  state.SetCanDraw(true);

  // Start a commit.
  state.SetNeedsCommit();
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
  state.OnBeginImplFrame(BeginFrameArgs::CreateForTesting());
  EXPECT_ACTION_UPDATE_STATE(
      SchedulerStateMachine::ACTION_SEND_BEGIN_MAIN_FRAME);
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
  EXPECT_TRUE(state.CommitPending());

  // Then initiate a draw.
  state.SetNeedsRedraw(true);
  state.OnBeginImplFrameDeadline();
  EXPECT_ACTION_UPDATE_STATE(
      SchedulerStateMachine::ACTION_DRAW_AND_SWAP_IF_POSSIBLE);

  // Fail the draw enough times to force a redraw,
  // then once more for good measure.
  for (int i = 0; i < draw_limit + 1; ++i) {
    state.DidDrawIfPossibleCompleted(
        DrawSwapReadbackResult::DRAW_ABORTED_CHECKERBOARD_ANIMATIONS);
  }
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
  EXPECT_TRUE(state.BeginImplFrameNeeded());
  EXPECT_TRUE(state.RedrawPending());
  // But the commit is ongoing.
  EXPECT_TRUE(state.CommitPending());
  EXPECT_TRUE(state.ForcedRedrawState() ==
              SchedulerStateMachine::FORCED_REDRAW_STATE_WAITING_FOR_COMMIT);

  state.NotifyBeginMainFrameStarted();
  state.NotifyReadyToCommit();
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_COMMIT);
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
  EXPECT_TRUE(state.RedrawPending());
  EXPECT_FALSE(state.CommitPending());

  // Now force redraw should be in waiting for activation
  EXPECT_TRUE(state.ForcedRedrawState() ==
    SchedulerStateMachine::FORCED_REDRAW_STATE_WAITING_FOR_ACTIVATION);

  // After failing additional draws, we should still be in a forced
  // redraw, but not back in WAITING_FOR_COMMIT.
  for (int i = 0; i < draw_limit + 1; ++i) {
    state.DidDrawIfPossibleCompleted(
        DrawSwapReadbackResult::DRAW_ABORTED_CHECKERBOARD_ANIMATIONS);
  }
  EXPECT_TRUE(state.RedrawPending());
  EXPECT_TRUE(state.ForcedRedrawState() ==
    SchedulerStateMachine::FORCED_REDRAW_STATE_WAITING_FOR_ACTIVATION);
}

TEST(SchedulerStateMachineTest, TestFailedDrawIsRetriedInNextBeginImplFrame) {
  SchedulerSettings default_scheduler_settings;
  StateMachine state(default_scheduler_settings);
  state.SetCanStart();
  state.UpdateState(state.NextAction());
  state.CreateAndInitializeOutputSurfaceWithActivatedCommit();
  state.SetVisible(true);
  state.SetCanDraw(true);

  // Start a draw.
  state.SetNeedsRedraw(true);
  EXPECT_TRUE(state.BeginImplFrameNeeded());
  state.OnBeginImplFrame(BeginFrameArgs::CreateForTesting());
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
  state.OnBeginImplFrameDeadline();
  EXPECT_TRUE(state.RedrawPending());
  EXPECT_ACTION_UPDATE_STATE(
      SchedulerStateMachine::ACTION_DRAW_AND_SWAP_IF_POSSIBLE);

  // Failing the draw for animation checkerboards makes us require a commit.
  state.DidDrawIfPossibleCompleted(
      DrawSwapReadbackResult::DRAW_ABORTED_CHECKERBOARD_ANIMATIONS);
  EXPECT_ACTION_UPDATE_STATE(
      SchedulerStateMachine::ACTION_SEND_BEGIN_MAIN_FRAME);
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
  EXPECT_TRUE(state.RedrawPending());

  // We should not be trying to draw again now, but we have a commit pending.
  EXPECT_TRUE(state.BeginImplFrameNeeded());
  state.OnBeginImplFrame(BeginFrameArgs::CreateForTesting());
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);

  // We should try to draw again at the end of the next BeginImplFrame on
  // the impl thread.
  state.OnBeginImplFrameDeadline();
  EXPECT_ACTION_UPDATE_STATE(
      SchedulerStateMachine::ACTION_DRAW_AND_SWAP_IF_POSSIBLE);
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
}

TEST(SchedulerStateMachineTest, TestDoestDrawTwiceInSameFrame) {
  SchedulerSettings default_scheduler_settings;
  StateMachine state(default_scheduler_settings);
  state.SetCanStart();
  state.UpdateState(state.NextAction());
  state.CreateAndInitializeOutputSurfaceWithActivatedCommit();
  state.SetVisible(true);
  state.SetCanDraw(true);
  state.SetNeedsRedraw(true);

  // Draw the first frame.
  EXPECT_TRUE(state.BeginImplFrameNeeded());
  state.OnBeginImplFrame(BeginFrameArgs::CreateForTesting());
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);

  state.OnBeginImplFrameDeadline();
  EXPECT_ACTION_UPDATE_STATE(
      SchedulerStateMachine::ACTION_DRAW_AND_SWAP_IF_POSSIBLE);
  state.DidDrawIfPossibleCompleted(DrawSwapReadbackResult::DRAW_SUCCESS);
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);

  // Before the next BeginImplFrame, set needs redraw again.
  // This should not redraw until the next BeginImplFrame.
  state.SetNeedsRedraw(true);
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);

  // Move to another frame. This should now draw.
  EXPECT_TRUE(state.BeginImplFrameNeeded());
  state.OnBeginImplFrame(BeginFrameArgs::CreateForTesting());

  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);

  state.OnBeginImplFrameDeadline();
  EXPECT_ACTION_UPDATE_STATE(
      SchedulerStateMachine::ACTION_DRAW_AND_SWAP_IF_POSSIBLE);
  state.DidDrawIfPossibleCompleted(DrawSwapReadbackResult::DRAW_SUCCESS);
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);

  // We just swapped, so we should proactively request another BeginImplFrame.
  EXPECT_TRUE(state.BeginImplFrameNeeded());
}

TEST(SchedulerStateMachineTest, TestNextActionDrawsOnBeginImplFrame) {
  SchedulerSettings default_scheduler_settings;

  // When not in BeginImplFrame deadline, or in BeginImplFrame deadline
  // but not visible, don't draw.
  size_t num_commit_states =
      sizeof(all_commit_states) / sizeof(SchedulerStateMachine::CommitState);
  size_t num_begin_impl_frame_states =
      sizeof(all_begin_impl_frame_states) /
      sizeof(SchedulerStateMachine::BeginImplFrameState);
  for (size_t i = 0; i < num_commit_states; ++i) {
    for (size_t j = 0; j < num_begin_impl_frame_states; ++j) {
      StateMachine state(default_scheduler_settings);
      state.SetCanStart();
      state.UpdateState(state.NextAction());
      state.CreateAndInitializeOutputSurfaceWithActivatedCommit();
      state.SetCommitState(all_commit_states[i]);
      state.SetBeginImplFrameState(all_begin_impl_frame_states[j]);
      bool visible =
          (all_begin_impl_frame_states[j] !=
           SchedulerStateMachine::BEGIN_IMPL_FRAME_STATE_INSIDE_DEADLINE);
      state.SetVisible(visible);

      // Case 1: needs_commit=false
      EXPECT_NE(SchedulerStateMachine::ACTION_DRAW_AND_SWAP_IF_POSSIBLE,
                state.NextAction());

      // Case 2: needs_commit=true
      state.SetNeedsCommit();
      EXPECT_NE(SchedulerStateMachine::ACTION_DRAW_AND_SWAP_IF_POSSIBLE,
                state.NextAction())
          << *state.AsValue();
    }
  }

  // When in BeginImplFrame deadline we should always draw for SetNeedsRedraw
  // except if we're ready to commit, in which case we expect a commit first.
  // SetNeedsForcedRedrawForReadback should take precedence over all and
  // issue a readback.
  for (size_t i = 0; i < num_commit_states; ++i) {
    for (size_t j = 0; j < 2; ++j) {
      bool request_readback = j;

      StateMachine state(default_scheduler_settings);
      state.SetCanStart();
      state.UpdateState(state.NextAction());
      state.CreateAndInitializeOutputSurfaceWithActivatedCommit();
      state.SetCanDraw(true);
      state.SetCommitState(all_commit_states[i]);
      state.SetBeginImplFrameState(
          SchedulerStateMachine::BEGIN_IMPL_FRAME_STATE_INSIDE_DEADLINE);
      if (request_readback) {
        state.SetNeedsForcedRedrawForReadback();
      } else {
        state.SetNeedsRedraw(true);
        state.SetVisible(true);
      }

      SchedulerStateMachine::Action expected_action;
      if (request_readback) {
        expected_action = SchedulerStateMachine::ACTION_DRAW_AND_READBACK;
      } else if (all_commit_states[i] ==
                 SchedulerStateMachine::COMMIT_STATE_READY_TO_COMMIT) {
        expected_action = SchedulerStateMachine::ACTION_COMMIT;
      } else {
        expected_action =
            SchedulerStateMachine::ACTION_DRAW_AND_SWAP_IF_POSSIBLE;
      }

      // Case 1: needs_commit=false.
      EXPECT_NE(state.BeginImplFrameNeeded(), request_readback)
          << *state.AsValue();
      EXPECT_EQ(state.NextAction(), expected_action) << *state.AsValue();

      // Case 2: needs_commit=true.
      state.SetNeedsCommit();
      EXPECT_NE(state.BeginImplFrameNeeded(), request_readback)
          << *state.AsValue();
      EXPECT_EQ(state.NextAction(), expected_action) << *state.AsValue();
    }
  }
}

TEST(SchedulerStateMachineTest, TestNoCommitStatesRedrawWhenInvisible) {
  SchedulerSettings default_scheduler_settings;

  size_t num_commit_states =
      sizeof(all_commit_states) / sizeof(SchedulerStateMachine::CommitState);
  for (size_t i = 0; i < num_commit_states; ++i) {
    // There shouldn't be any drawing regardless of BeginImplFrame.
    for (size_t j = 0; j < 2; ++j) {
      StateMachine state(default_scheduler_settings);
      state.SetCanStart();
      state.UpdateState(state.NextAction());
      state.CreateAndInitializeOutputSurfaceWithActivatedCommit();
      state.SetCommitState(all_commit_states[i]);
      state.SetVisible(false);
      state.SetNeedsRedraw(true);
      if (j == 1) {
        state.SetBeginImplFrameState(
            SchedulerStateMachine::BEGIN_IMPL_FRAME_STATE_INSIDE_DEADLINE);
      }

      // Case 1: needs_commit=false.
      EXPECT_NE(SchedulerStateMachine::ACTION_DRAW_AND_SWAP_IF_POSSIBLE,
                state.NextAction());

      // Case 2: needs_commit=true.
      state.SetNeedsCommit();
      EXPECT_NE(SchedulerStateMachine::ACTION_DRAW_AND_SWAP_IF_POSSIBLE,
                state.NextAction())
          << *state.AsValue();
    }
  }
}

TEST(SchedulerStateMachineTest, TestCanRedraw_StopsDraw) {
  SchedulerSettings default_scheduler_settings;

  size_t num_commit_states =
      sizeof(all_commit_states) / sizeof(SchedulerStateMachine::CommitState);
  for (size_t i = 0; i < num_commit_states; ++i) {
    // There shouldn't be any drawing regardless of BeginImplFrame.
    for (size_t j = 0; j < 2; ++j) {
      StateMachine state(default_scheduler_settings);
      state.SetCanStart();
      state.UpdateState(state.NextAction());
      state.CreateAndInitializeOutputSurfaceWithActivatedCommit();
      state.SetCommitState(all_commit_states[i]);
      state.SetVisible(false);
      state.SetNeedsRedraw(true);
      if (j == 1)
        state.OnBeginImplFrame(BeginFrameArgs::CreateForTesting());

      state.SetCanDraw(false);
      EXPECT_NE(SchedulerStateMachine::ACTION_DRAW_AND_SWAP_IF_POSSIBLE,
                state.NextAction());
    }
  }
}

TEST(SchedulerStateMachineTest,
     TestCanRedrawWithWaitingForFirstDrawMakesProgress) {
  SchedulerSettings default_scheduler_settings;
  StateMachine state(default_scheduler_settings);
  state.SetCanStart();
  state.UpdateState(state.NextAction());
  state.CreateAndInitializeOutputSurfaceWithActivatedCommit();

  state.SetActiveTreeNeedsFirstDraw(true);
  state.SetNeedsCommit();
  state.SetNeedsRedraw(true);
  state.SetVisible(true);
  state.SetCanDraw(false);
  state.OnBeginImplFrame(BeginFrameArgs::CreateForTesting());
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_DRAW_AND_SWAP_ABORT);
  EXPECT_ACTION_UPDATE_STATE(
      SchedulerStateMachine::ACTION_SEND_BEGIN_MAIN_FRAME);
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
  state.NotifyBeginMainFrameStarted();
  state.NotifyReadyToCommit();
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_COMMIT);
  state.OnBeginImplFrameDeadline();
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_DRAW_AND_SWAP_ABORT);
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
}

void TestSetNeedsCommitIsNotLost(bool main_frame_before_draw_enabled) {
  SchedulerSettings scheduler_settings;
  scheduler_settings.main_frame_before_draw_enabled =
      main_frame_before_draw_enabled;
  StateMachine state(scheduler_settings);
  state.SetCanStart();
  state.UpdateState(state.NextAction());
  state.CreateAndInitializeOutputSurfaceWithActivatedCommit();
  state.SetNeedsCommit();
  state.SetVisible(true);
  state.SetCanDraw(true);

  EXPECT_TRUE(state.BeginImplFrameNeeded());

  // Begin the frame.
  state.OnBeginImplFrame(BeginFrameArgs::CreateForTesting());
  EXPECT_ACTION_UPDATE_STATE(
      SchedulerStateMachine::ACTION_SEND_BEGIN_MAIN_FRAME);
  EXPECT_EQ(SchedulerStateMachine::COMMIT_STATE_BEGIN_MAIN_FRAME_SENT,
            state.CommitState());

  // Now, while the frame is in progress, set another commit.
  state.SetNeedsCommit();
  EXPECT_TRUE(state.NeedsCommit());

  // Let the frame finish.
  state.NotifyBeginMainFrameStarted();
  state.NotifyReadyToCommit();
  EXPECT_EQ(SchedulerStateMachine::COMMIT_STATE_READY_TO_COMMIT,
            state.CommitState());

  // Expect to commit regardless of BeginImplFrame state.
  EXPECT_EQ(SchedulerStateMachine::BEGIN_IMPL_FRAME_STATE_BEGIN_FRAME_STARTING,
            state.begin_impl_frame_state());
  EXPECT_EQ(SchedulerStateMachine::ACTION_COMMIT, state.NextAction());

  state.OnBeginImplFrameDeadlinePending();
  EXPECT_EQ(SchedulerStateMachine::BEGIN_IMPL_FRAME_STATE_INSIDE_BEGIN_FRAME,
            state.begin_impl_frame_state());
  EXPECT_EQ(SchedulerStateMachine::ACTION_COMMIT, state.NextAction());

  state.OnBeginImplFrameDeadline();
  EXPECT_EQ(SchedulerStateMachine::BEGIN_IMPL_FRAME_STATE_INSIDE_DEADLINE,
            state.begin_impl_frame_state());
  EXPECT_EQ(SchedulerStateMachine::ACTION_COMMIT, state.NextAction());

  state.OnBeginImplFrameIdle();
  EXPECT_EQ(SchedulerStateMachine::BEGIN_IMPL_FRAME_STATE_IDLE,
            state.begin_impl_frame_state());
  EXPECT_EQ(SchedulerStateMachine::ACTION_COMMIT, state.NextAction());

  state.OnBeginImplFrame(BeginFrameArgs::CreateForTesting());
  EXPECT_EQ(SchedulerStateMachine::BEGIN_IMPL_FRAME_STATE_BEGIN_FRAME_STARTING,
            state.begin_impl_frame_state());
  EXPECT_EQ(SchedulerStateMachine::ACTION_COMMIT, state.NextAction());

  // Finish the commit, then make sure we start the next commit immediately
  // and draw on the next BeginImplFrame.
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_COMMIT);
  if (main_frame_before_draw_enabled) {
    EXPECT_ACTION_UPDATE_STATE(
        SchedulerStateMachine::ACTION_SEND_BEGIN_MAIN_FRAME);
  }
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);

  state.OnBeginImplFrameDeadline();

  EXPECT_TRUE(state.active_tree_needs_first_draw());
  EXPECT_ACTION_UPDATE_STATE(
      SchedulerStateMachine::ACTION_DRAW_AND_SWAP_IF_POSSIBLE);
  state.DidDrawIfPossibleCompleted(DrawSwapReadbackResult::DRAW_SUCCESS);
  if (!main_frame_before_draw_enabled) {
    EXPECT_ACTION_UPDATE_STATE(
        SchedulerStateMachine::ACTION_SEND_BEGIN_MAIN_FRAME);
  }
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
}

TEST(SchedulerStateMachineTest, TestSetNeedsCommitIsNotLost) {
  bool main_frame_before_draw_enabled = false;
  TestSetNeedsCommitIsNotLost(main_frame_before_draw_enabled);
}

TEST(SchedulerStateMachineTest, TestSetNeedsCommitIsNotLost_CommitBeforeDraw) {
  bool main_frame_before_draw_enabled = true;
  TestSetNeedsCommitIsNotLost(main_frame_before_draw_enabled);
}

TEST(SchedulerStateMachineTest, TestFullCycle) {
  SchedulerSettings default_scheduler_settings;
  StateMachine state(default_scheduler_settings);
  state.SetCanStart();
  state.UpdateState(state.NextAction());
  state.CreateAndInitializeOutputSurfaceWithActivatedCommit();
  state.SetVisible(true);
  state.SetCanDraw(true);

  // Start clean and set commit.
  state.SetNeedsCommit();

  // Begin the frame.
  state.OnBeginImplFrame(BeginFrameArgs::CreateForTesting());
  EXPECT_ACTION_UPDATE_STATE(
      SchedulerStateMachine::ACTION_SEND_BEGIN_MAIN_FRAME);
  EXPECT_EQ(SchedulerStateMachine::COMMIT_STATE_BEGIN_MAIN_FRAME_SENT,
            state.CommitState());
  EXPECT_FALSE(state.NeedsCommit());
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);

  // Tell the scheduler the frame finished.
  state.NotifyBeginMainFrameStarted();
  state.NotifyReadyToCommit();
  EXPECT_EQ(SchedulerStateMachine::COMMIT_STATE_READY_TO_COMMIT,
            state.CommitState());

  // Commit.
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_COMMIT);
  EXPECT_TRUE(state.active_tree_needs_first_draw());
  EXPECT_TRUE(state.needs_redraw());

  // Expect to do nothing until BeginImplFrame deadline
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);

  // At BeginImplFrame deadline, draw.
  state.OnBeginImplFrameDeadline();
  EXPECT_ACTION_UPDATE_STATE(
      SchedulerStateMachine::ACTION_DRAW_AND_SWAP_IF_POSSIBLE);
  state.DidDrawIfPossibleCompleted(DrawSwapReadbackResult::DRAW_SUCCESS);

  // Should be synchronized, no draw needed, no action needed.
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
  EXPECT_EQ(SchedulerStateMachine::COMMIT_STATE_IDLE, state.CommitState());
  EXPECT_FALSE(state.needs_redraw());
}

TEST(SchedulerStateMachineTest, TestFullCycleWithCommitRequestInbetween) {
  SchedulerSettings default_scheduler_settings;
  StateMachine state(default_scheduler_settings);
  state.SetCanStart();
  state.UpdateState(state.NextAction());
  state.CreateAndInitializeOutputSurfaceWithActivatedCommit();
  state.SetVisible(true);
  state.SetCanDraw(true);

  // Start clean and set commit.
  state.SetNeedsCommit();

  // Begin the frame.
  state.OnBeginImplFrame(BeginFrameArgs::CreateForTesting());
  EXPECT_ACTION_UPDATE_STATE(
      SchedulerStateMachine::ACTION_SEND_BEGIN_MAIN_FRAME);
  EXPECT_EQ(SchedulerStateMachine::COMMIT_STATE_BEGIN_MAIN_FRAME_SENT,
            state.CommitState());
  EXPECT_FALSE(state.NeedsCommit());
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);

  // Request another commit while the commit is in flight.
  state.SetNeedsCommit();
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);

  // Tell the scheduler the frame finished.
  state.NotifyBeginMainFrameStarted();
  state.NotifyReadyToCommit();
  EXPECT_EQ(SchedulerStateMachine::COMMIT_STATE_READY_TO_COMMIT,
            state.CommitState());

  // First commit.
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_COMMIT);
  EXPECT_TRUE(state.active_tree_needs_first_draw());
  EXPECT_TRUE(state.needs_redraw());

  // Expect to do nothing until BeginImplFrame deadline.
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);

  // At BeginImplFrame deadline, draw.
  state.OnBeginImplFrameDeadline();
  EXPECT_ACTION_UPDATE_STATE(
      SchedulerStateMachine::ACTION_DRAW_AND_SWAP_IF_POSSIBLE);
  state.DidDrawIfPossibleCompleted(DrawSwapReadbackResult::DRAW_SUCCESS);

  // Should be synchronized, no draw needed, no action needed.
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
  EXPECT_EQ(SchedulerStateMachine::COMMIT_STATE_IDLE, state.CommitState());
  EXPECT_FALSE(state.needs_redraw());

  // Next BeginImplFrame should initiate second commit.
  state.OnBeginImplFrame(BeginFrameArgs::CreateForTesting());
  EXPECT_ACTION_UPDATE_STATE(
      SchedulerStateMachine::ACTION_SEND_BEGIN_MAIN_FRAME);
}

TEST(SchedulerStateMachineTest, TestRequestCommitInvisible) {
  SchedulerSettings default_scheduler_settings;
  StateMachine state(default_scheduler_settings);
  state.SetCanStart();
  state.UpdateState(state.NextAction());
  state.CreateAndInitializeOutputSurfaceWithActivatedCommit();
  state.SetNeedsCommit();
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
}

TEST(SchedulerStateMachineTest, TestGoesInvisibleBeforeFinishCommit) {
  SchedulerSettings default_scheduler_settings;
  StateMachine state(default_scheduler_settings);
  state.SetCanStart();
  state.UpdateState(state.NextAction());
  state.CreateAndInitializeOutputSurfaceWithActivatedCommit();
  state.SetVisible(true);
  state.SetCanDraw(true);

  // Start clean and set commit.
  state.SetNeedsCommit();

  // Begin the frame while visible.
  state.OnBeginImplFrame(BeginFrameArgs::CreateForTesting());
  EXPECT_ACTION_UPDATE_STATE(
      SchedulerStateMachine::ACTION_SEND_BEGIN_MAIN_FRAME);
  EXPECT_EQ(SchedulerStateMachine::COMMIT_STATE_BEGIN_MAIN_FRAME_SENT,
            state.CommitState());
  EXPECT_FALSE(state.NeedsCommit());
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);

  // Become invisible and abort BeginMainFrame.
  state.SetVisible(false);
  state.BeginMainFrameAborted(false);

  // We should now be back in the idle state as if we never started the frame.
  EXPECT_EQ(SchedulerStateMachine::COMMIT_STATE_IDLE, state.CommitState());
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);

  // We shouldn't do anything on the BeginImplFrame deadline.
  state.OnBeginImplFrameDeadline();
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);

  // Become visible again.
  state.SetVisible(true);

  // Although we have aborted on this frame and haven't cancelled the commit
  // (i.e. need another), don't send another BeginMainFrame yet.
  EXPECT_EQ(SchedulerStateMachine::COMMIT_STATE_IDLE, state.CommitState());
  EXPECT_EQ(SchedulerStateMachine::ACTION_NONE, state.NextAction());
  EXPECT_TRUE(state.NeedsCommit());

  // Start a new frame.
  state.OnBeginImplFrame(BeginFrameArgs::CreateForTesting());
  EXPECT_ACTION_UPDATE_STATE(
      SchedulerStateMachine::ACTION_SEND_BEGIN_MAIN_FRAME);

  // We should be starting the commit now.
  EXPECT_EQ(SchedulerStateMachine::COMMIT_STATE_BEGIN_MAIN_FRAME_SENT,
            state.CommitState());
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
}

TEST(SchedulerStateMachineTest, AbortBeginMainFrameAndCancelCommit) {
  SchedulerSettings default_scheduler_settings;
  StateMachine state(default_scheduler_settings);
  state.SetCanStart();
  state.UpdateState(state.NextAction());
  state.DidCreateAndInitializeOutputSurface();
  state.SetVisible(true);
  state.SetCanDraw(true);

  // Get into a begin frame / commit state.
  state.SetNeedsCommit();

  EXPECT_ACTION_UPDATE_STATE(
      SchedulerStateMachine::ACTION_SEND_BEGIN_MAIN_FRAME);
  EXPECT_EQ(SchedulerStateMachine::COMMIT_STATE_BEGIN_MAIN_FRAME_SENT,
            state.CommitState());
  EXPECT_FALSE(state.NeedsCommit());
  EXPECT_EQ(SchedulerStateMachine::ACTION_NONE, state.NextAction());

  // Abort the commit, cancelling future commits.
  state.BeginMainFrameAborted(true);

  // Verify that another commit doesn't start on the same frame.
  EXPECT_EQ(SchedulerStateMachine::COMMIT_STATE_IDLE, state.CommitState());
  EXPECT_EQ(SchedulerStateMachine::ACTION_NONE, state.NextAction());
  EXPECT_FALSE(state.NeedsCommit());

  // Start a new frame; draw because this is the first frame since output
  // surface init'd.
  state.OnBeginImplFrame(BeginFrameArgs::CreateForTesting());
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
  state.OnBeginImplFrameDeadline();
  EXPECT_ACTION_UPDATE_STATE(
      SchedulerStateMachine::ACTION_DRAW_AND_SWAP_IF_POSSIBLE);

  // Verify another commit doesn't start on another frame either.
  EXPECT_EQ(SchedulerStateMachine::COMMIT_STATE_IDLE, state.CommitState());
  EXPECT_EQ(SchedulerStateMachine::ACTION_NONE, state.NextAction());
  EXPECT_FALSE(state.NeedsCommit());

  // Verify another commit can start if requested, though.
  state.SetNeedsCommit();
  EXPECT_EQ(SchedulerStateMachine::COMMIT_STATE_IDLE, state.CommitState());
  EXPECT_EQ(SchedulerStateMachine::ACTION_SEND_BEGIN_MAIN_FRAME,
            state.NextAction());
}

TEST(SchedulerStateMachineTest, TestFirstContextCreation) {
  SchedulerSettings default_scheduler_settings;
  StateMachine state(default_scheduler_settings);
  state.SetCanStart();
  state.SetVisible(true);
  state.SetCanDraw(true);

  EXPECT_ACTION_UPDATE_STATE(
      SchedulerStateMachine::ACTION_BEGIN_OUTPUT_SURFACE_CREATION);
  state.CreateAndInitializeOutputSurfaceWithActivatedCommit();
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);

  // Check that the first init does not SetNeedsCommit.
  state.OnBeginImplFrame(BeginFrameArgs::CreateForTesting());
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
  state.OnBeginImplFrameDeadline();
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);

  // Check that a needs commit initiates a BeginMainFrame.
  state.SetNeedsCommit();
  state.OnBeginImplFrame(BeginFrameArgs::CreateForTesting());
  EXPECT_ACTION_UPDATE_STATE(
      SchedulerStateMachine::ACTION_SEND_BEGIN_MAIN_FRAME);
}

TEST(SchedulerStateMachineTest, TestContextLostWhenCompletelyIdle) {
  SchedulerSettings default_scheduler_settings;
  StateMachine state(default_scheduler_settings);
  state.SetCanStart();
  state.UpdateState(state.NextAction());
  state.CreateAndInitializeOutputSurfaceWithActivatedCommit();

  state.SetVisible(true);
  state.SetCanDraw(true);

  EXPECT_NE(SchedulerStateMachine::ACTION_BEGIN_OUTPUT_SURFACE_CREATION,
            state.NextAction());
  state.DidLoseOutputSurface();

  EXPECT_EQ(SchedulerStateMachine::ACTION_BEGIN_OUTPUT_SURFACE_CREATION,
            state.NextAction());
  state.UpdateState(state.NextAction());

  // Once context recreation begins, nothing should happen.
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);

  // Recreate the context.
  state.CreateAndInitializeOutputSurfaceWithActivatedCommit();

  // When the context is recreated, we should begin a commit.
  state.OnBeginImplFrame(BeginFrameArgs::CreateForTesting());
  EXPECT_ACTION_UPDATE_STATE(
      SchedulerStateMachine::ACTION_SEND_BEGIN_MAIN_FRAME);
}

TEST(SchedulerStateMachineTest,
     TestContextLostWhenIdleAndCommitRequestedWhileRecreating) {
  SchedulerSettings default_scheduler_settings;
  StateMachine state(default_scheduler_settings);
  state.SetCanStart();
  state.UpdateState(state.NextAction());
  state.CreateAndInitializeOutputSurfaceWithActivatedCommit();
  state.SetVisible(true);
  state.SetCanDraw(true);

  EXPECT_NE(SchedulerStateMachine::ACTION_BEGIN_OUTPUT_SURFACE_CREATION,
            state.NextAction());
  state.DidLoseOutputSurface();

  EXPECT_ACTION_UPDATE_STATE(
      SchedulerStateMachine::ACTION_BEGIN_OUTPUT_SURFACE_CREATION);
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);

  // Once context recreation begins, nothing should happen.
  state.OnBeginImplFrame(BeginFrameArgs::CreateForTesting());
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
  state.OnBeginImplFrameDeadline();
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);

  // While context is recreating, commits shouldn't begin.
  state.SetNeedsCommit();
  state.OnBeginImplFrame(BeginFrameArgs::CreateForTesting());
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
  state.OnBeginImplFrameDeadline();
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);

  // Recreate the context
  state.DidCreateAndInitializeOutputSurface();
  EXPECT_FALSE(state.RedrawPending());

  // When the context is recreated, we should begin a commit
  EXPECT_ACTION_UPDATE_STATE(
      SchedulerStateMachine::ACTION_SEND_BEGIN_MAIN_FRAME);
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
  EXPECT_EQ(SchedulerStateMachine::COMMIT_STATE_BEGIN_MAIN_FRAME_SENT,
            state.CommitState());

  state.NotifyBeginMainFrameStarted();
  state.NotifyReadyToCommit();
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_COMMIT);
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
  // Finishing the first commit after initializing an output surface should
  // automatically cause a redraw.
  EXPECT_TRUE(state.RedrawPending());

  // Once the context is recreated, whether we draw should be based on
  // SetCanDraw.
  state.OnBeginImplFrame(BeginFrameArgs::CreateForTesting());
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
  state.OnBeginImplFrameDeadline();
  EXPECT_EQ(SchedulerStateMachine::ACTION_DRAW_AND_SWAP_IF_POSSIBLE,
            state.NextAction());
  state.SetCanDraw(false);
  EXPECT_EQ(SchedulerStateMachine::ACTION_DRAW_AND_SWAP_ABORT,
            state.NextAction());
  state.SetCanDraw(true);
  EXPECT_EQ(SchedulerStateMachine::ACTION_DRAW_AND_SWAP_IF_POSSIBLE,
            state.NextAction());
}

TEST(SchedulerStateMachineTest, TestContextLostWhileCommitInProgress) {
  SchedulerSettings scheduler_settings;
  StateMachine state(scheduler_settings);
  state.SetCanStart();
  state.UpdateState(state.NextAction());
  state.CreateAndInitializeOutputSurfaceWithActivatedCommit();
  state.SetVisible(true);
  state.SetCanDraw(true);

  // Get a commit in flight.
  state.SetNeedsCommit();

  // Set damage and expect a draw.
  state.SetNeedsRedraw(true);
  state.OnBeginImplFrame(BeginFrameArgs::CreateForTesting());
  EXPECT_ACTION_UPDATE_STATE(
      SchedulerStateMachine::ACTION_SEND_BEGIN_MAIN_FRAME);
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
  state.OnBeginImplFrameDeadline();
  EXPECT_ACTION_UPDATE_STATE(
      SchedulerStateMachine::ACTION_DRAW_AND_SWAP_IF_POSSIBLE);
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);

  // Cause a lost context while the BeginMainFrame is in flight.
  state.DidLoseOutputSurface();

  // Ask for another draw. Expect nothing happens.
  state.SetNeedsRedraw(true);
  EXPECT_EQ(SchedulerStateMachine::ACTION_NONE, state.NextAction());

  // Finish the frame, and commit.
  state.NotifyBeginMainFrameStarted();
  state.NotifyReadyToCommit();
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_COMMIT);

  // We will abort the draw when the output surface is lost if we are
  // waiting for the first draw to unblock the main thread.
  EXPECT_TRUE(state.active_tree_needs_first_draw());
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_DRAW_AND_SWAP_ABORT);

  // Expect to begin context recreation only in BEGIN_IMPL_FRAME_STATE_IDLE
  EXPECT_EQ(SchedulerStateMachine::BEGIN_IMPL_FRAME_STATE_IDLE,
            state.begin_impl_frame_state());
  EXPECT_EQ(SchedulerStateMachine::ACTION_BEGIN_OUTPUT_SURFACE_CREATION,
            state.NextAction());

  state.OnBeginImplFrame(BeginFrameArgs::CreateForTesting());
  EXPECT_EQ(SchedulerStateMachine::BEGIN_IMPL_FRAME_STATE_BEGIN_FRAME_STARTING,
            state.begin_impl_frame_state());
  EXPECT_EQ(SchedulerStateMachine::ACTION_NONE, state.NextAction());

  state.OnBeginImplFrameDeadlinePending();
  EXPECT_EQ(SchedulerStateMachine::BEGIN_IMPL_FRAME_STATE_INSIDE_BEGIN_FRAME,
            state.begin_impl_frame_state());
  EXPECT_EQ(SchedulerStateMachine::ACTION_NONE, state.NextAction());

  state.OnBeginImplFrameDeadline();
  EXPECT_EQ(SchedulerStateMachine::BEGIN_IMPL_FRAME_STATE_INSIDE_DEADLINE,
            state.begin_impl_frame_state());
  EXPECT_EQ(SchedulerStateMachine::ACTION_NONE, state.NextAction());
}

TEST(SchedulerStateMachineTest,
     TestContextLostWhileCommitInProgressAndAnotherCommitRequested) {
  SchedulerSettings scheduler_settings;
  StateMachine state(scheduler_settings);
  state.SetCanStart();
  state.UpdateState(state.NextAction());
  state.CreateAndInitializeOutputSurfaceWithActivatedCommit();
  state.SetVisible(true);
  state.SetCanDraw(true);

  // Get a commit in flight.
  state.SetNeedsCommit();
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);

  // Set damage and expect a draw.
  state.SetNeedsRedraw(true);
  state.OnBeginImplFrame(BeginFrameArgs::CreateForTesting());
  EXPECT_ACTION_UPDATE_STATE(
      SchedulerStateMachine::ACTION_SEND_BEGIN_MAIN_FRAME);
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
  state.OnBeginImplFrameDeadline();
  EXPECT_ACTION_UPDATE_STATE(
      SchedulerStateMachine::ACTION_DRAW_AND_SWAP_IF_POSSIBLE);
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);

  // Cause a lost context while the BeginMainFrame is in flight.
  state.DidLoseOutputSurface();

  // Ask for another draw and also set needs commit. Expect nothing happens.
  state.SetNeedsRedraw(true);
  state.SetNeedsCommit();
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);

  // Finish the frame, and commit.
  state.NotifyBeginMainFrameStarted();
  state.NotifyReadyToCommit();
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_COMMIT);
  EXPECT_TRUE(state.active_tree_needs_first_draw());

  // Because the output surface is missing, we expect the draw to abort.
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_DRAW_AND_SWAP_ABORT);

  // Expect to begin context recreation only in BEGIN_IMPL_FRAME_STATE_IDLE
  EXPECT_EQ(SchedulerStateMachine::BEGIN_IMPL_FRAME_STATE_IDLE,
            state.begin_impl_frame_state());
  EXPECT_EQ(SchedulerStateMachine::ACTION_BEGIN_OUTPUT_SURFACE_CREATION,
            state.NextAction());

  state.OnBeginImplFrame(BeginFrameArgs::CreateForTesting());
  EXPECT_EQ(SchedulerStateMachine::BEGIN_IMPL_FRAME_STATE_BEGIN_FRAME_STARTING,
            state.begin_impl_frame_state());
  EXPECT_EQ(SchedulerStateMachine::ACTION_NONE, state.NextAction());

  state.OnBeginImplFrameDeadlinePending();
  EXPECT_EQ(SchedulerStateMachine::BEGIN_IMPL_FRAME_STATE_INSIDE_BEGIN_FRAME,
            state.begin_impl_frame_state());
  EXPECT_EQ(SchedulerStateMachine::ACTION_NONE, state.NextAction());

  state.OnBeginImplFrameDeadline();
  EXPECT_EQ(SchedulerStateMachine::BEGIN_IMPL_FRAME_STATE_INSIDE_DEADLINE,
            state.begin_impl_frame_state());
  EXPECT_EQ(SchedulerStateMachine::ACTION_NONE, state.NextAction());

  state.OnBeginImplFrameIdle();
  EXPECT_ACTION_UPDATE_STATE(
      SchedulerStateMachine::ACTION_BEGIN_OUTPUT_SURFACE_CREATION);

  // After we get a new output surface, the commit flow should start.
  state.CreateAndInitializeOutputSurfaceWithActivatedCommit();
  state.OnBeginImplFrame(BeginFrameArgs::CreateForTesting());
  EXPECT_ACTION_UPDATE_STATE(
      SchedulerStateMachine::ACTION_SEND_BEGIN_MAIN_FRAME);
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
  state.NotifyBeginMainFrameStarted();
  state.NotifyReadyToCommit();
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_COMMIT);
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
  state.OnBeginImplFrameDeadline();
  EXPECT_ACTION_UPDATE_STATE(
      SchedulerStateMachine::ACTION_DRAW_AND_SWAP_IF_POSSIBLE);
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
}

TEST(SchedulerStateMachineTest, TestFinishAllRenderingWhileContextLost) {
  SchedulerSettings default_scheduler_settings;
  StateMachine state(default_scheduler_settings);
  state.SetCanStart();
  state.UpdateState(state.NextAction());
  state.CreateAndInitializeOutputSurfaceWithActivatedCommit();
  state.SetVisible(true);
  state.SetCanDraw(true);

  // Cause a lost context lost.
  state.DidLoseOutputSurface();

  // Ask a forced redraw for readback and verify it ocurrs.
  state.SetNeedsForcedRedrawForReadback();
  state.OnBeginImplFrame(BeginFrameArgs::CreateForTesting());
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_DRAW_AND_READBACK);
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);

  // Forced redraws for readbacks need to be followed by a new commit
  // to replace the readback commit.
  EXPECT_EQ(SchedulerStateMachine::COMMIT_STATE_BEGIN_MAIN_FRAME_SENT,
            state.CommitState());
  state.NotifyBeginMainFrameStarted();
  state.NotifyReadyToCommit();
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_COMMIT);

  // We don't yet have an output surface, so we the draw and swap should abort.
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_DRAW_AND_SWAP_ABORT);

  // Expect to begin context recreation only in BEGIN_IMPL_FRAME_STATE_IDLE
  EXPECT_EQ(SchedulerStateMachine::ACTION_NONE, state.NextAction());

  state.OnBeginImplFrameDeadline();
  EXPECT_EQ(SchedulerStateMachine::ACTION_NONE, state.NextAction());

  state.OnBeginImplFrameIdle();
  EXPECT_ACTION_UPDATE_STATE(
      SchedulerStateMachine::ACTION_BEGIN_OUTPUT_SURFACE_CREATION);

  // Ask a readback and verify it occurs.
  state.SetNeedsForcedRedrawForReadback();
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_DRAW_AND_READBACK);
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
}

TEST(SchedulerStateMachineTest, DontDrawBeforeCommitAfterLostOutputSurface) {
  SchedulerSettings default_scheduler_settings;
  StateMachine state(default_scheduler_settings);
  state.SetCanStart();
  state.UpdateState(state.NextAction());
  state.CreateAndInitializeOutputSurfaceWithActivatedCommit();
  state.SetVisible(true);
  state.SetCanDraw(true);

  state.SetNeedsRedraw(true);

  // Cause a lost output surface, and restore it.
  state.DidLoseOutputSurface();
  EXPECT_EQ(SchedulerStateMachine::ACTION_BEGIN_OUTPUT_SURFACE_CREATION,
            state.NextAction());
  state.UpdateState(state.NextAction());
  state.DidCreateAndInitializeOutputSurface();

  EXPECT_FALSE(state.RedrawPending());
  state.OnBeginImplFrame(BeginFrameArgs::CreateForTesting());
  EXPECT_EQ(SchedulerStateMachine::ACTION_SEND_BEGIN_MAIN_FRAME,
            state.NextAction());
}

TEST(SchedulerStateMachineTest,
     TestPendingActivationsShouldBeForcedAfterLostOutputSurface) {
  SchedulerSettings settings;
  settings.impl_side_painting = true;
  StateMachine state(settings);
  state.SetCanStart();
  state.UpdateState(state.NextAction());
  state.CreateAndInitializeOutputSurfaceWithActivatedCommit();
  state.SetVisible(true);
  state.SetCanDraw(true);

  state.SetCommitState(
      SchedulerStateMachine::COMMIT_STATE_BEGIN_MAIN_FRAME_SENT);

  // Cause a lost context.
  state.DidLoseOutputSurface();

  state.NotifyBeginMainFrameStarted();
  state.NotifyReadyToCommit();
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_COMMIT);

  EXPECT_TRUE(state.PendingActivationsShouldBeForced());
  EXPECT_ACTION_UPDATE_STATE(
      SchedulerStateMachine::ACTION_ACTIVATE_PENDING_TREE);

  EXPECT_TRUE(state.PendingDrawsShouldBeAborted());
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_DRAW_AND_SWAP_ABORT);
}

TEST(SchedulerStateMachineTest,
     TestSendBeginMainFrameWhenInvisibleAndForceCommit) {
  SchedulerSettings default_scheduler_settings;
  StateMachine state(default_scheduler_settings);
  state.SetCanStart();
  state.UpdateState(state.NextAction());
  state.CreateAndInitializeOutputSurfaceWithActivatedCommit();
  state.SetVisible(false);
  state.SetNeedsForcedCommitForReadback();
  EXPECT_EQ(SchedulerStateMachine::ACTION_SEND_BEGIN_MAIN_FRAME,
            state.NextAction());
}

TEST(SchedulerStateMachineTest,
     TestSendBeginMainFrameWhenCanStartFalseAndForceCommit) {
  SchedulerSettings default_scheduler_settings;
  StateMachine state(default_scheduler_settings);
  state.SetVisible(true);
  state.SetCanDraw(true);
  state.SetNeedsForcedCommitForReadback();
  EXPECT_EQ(SchedulerStateMachine::ACTION_SEND_BEGIN_MAIN_FRAME,
            state.NextAction());
}

// If new commit is not requested explicitly after starting forced commit,
// new commit should not scheduled after drawing the replacement commit.
TEST(SchedulerStateMachineTest, DontMakeNewCommitAfterDrawingReplaceCommit) {
  SchedulerSettings default_scheduler_settings;
  StateMachine state(default_scheduler_settings);
  state.SetCanStart();
  state.UpdateState(state.NextAction());
  state.CreateAndInitializeOutputSurfaceWithActivatedCommit();
  state.SetVisible(true);
  state.SetCanDraw(true);

  // There is a scheduled commit.
  state.SetCommitState(
      SchedulerStateMachine::COMMIT_STATE_BEGIN_MAIN_FRAME_SENT);

  // Request a forced commit.
  state.SetNeedsForcedCommitForReadback();

  state.NotifyBeginMainFrameStarted();
  state.NotifyReadyToCommit();
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_COMMIT);
  EXPECT_EQ(SchedulerStateMachine::ACTION_DRAW_AND_READBACK,
            state.NextAction());
  state.UpdateState(state.NextAction());
  EXPECT_EQ(
      SchedulerStateMachine::READBACK_STATE_WAITING_FOR_REPLACEMENT_COMMIT,
      state.readback_state());
  EXPECT_EQ(SchedulerStateMachine::COMMIT_STATE_BEGIN_MAIN_FRAME_SENT,
            state.CommitState());

  // Finish the replacement commit.
  state.NotifyBeginMainFrameStarted();
  state.NotifyReadyToCommit();
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_COMMIT);

  state.OnBeginImplFrame(BeginFrameArgs::CreateForTesting());
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
  state.OnBeginImplFrameDeadline();
  EXPECT_ACTION_UPDATE_STATE(
      SchedulerStateMachine::ACTION_DRAW_AND_SWAP_IF_POSSIBLE);
  EXPECT_EQ(SchedulerStateMachine::READBACK_STATE_IDLE, state.readback_state());
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
}

TEST(SchedulerStateMachineTest, TestFinishCommitWhenCommitInProgress) {
  SchedulerSettings default_scheduler_settings;
  StateMachine state(default_scheduler_settings);
  state.SetCanStart();
  state.UpdateState(state.NextAction());
  state.CreateAndInitializeOutputSurfaceWithActivatedCommit();
  state.SetVisible(false);
  state.SetCommitState(
      SchedulerStateMachine::COMMIT_STATE_BEGIN_MAIN_FRAME_SENT);
  state.SetNeedsCommit();

  state.NotifyBeginMainFrameStarted();
  state.NotifyReadyToCommit();
  EXPECT_EQ(SchedulerStateMachine::ACTION_COMMIT, state.NextAction());
  state.UpdateState(state.NextAction());

  EXPECT_TRUE(state.active_tree_needs_first_draw());
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_DRAW_AND_SWAP_ABORT);
}

TEST(SchedulerStateMachineTest, TestFinishCommitWhenForcedCommitInProgress) {
  SchedulerSettings default_scheduler_settings;
  StateMachine state(default_scheduler_settings);
  state.SetCanStart();
  state.UpdateState(state.NextAction());
  state.CreateAndInitializeOutputSurfaceWithActivatedCommit();
  state.SetVisible(false);
  state.SetCommitState(
      SchedulerStateMachine::COMMIT_STATE_BEGIN_MAIN_FRAME_SENT);
  state.SetNeedsForcedCommitForReadback();

  // The commit for readback interupts the normal commit.
  state.NotifyBeginMainFrameStarted();
  state.NotifyReadyToCommit();
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_COMMIT);

  EXPECT_TRUE(state.active_tree_needs_first_draw());
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_DRAW_AND_READBACK);

  // When the readback interrupts the normal commit, we should not get
  // another BeginMainFrame when the readback completes.
  EXPECT_NE(SchedulerStateMachine::ACTION_SEND_BEGIN_MAIN_FRAME,
            state.NextAction());

  // The normal commit can then proceed.
  state.NotifyBeginMainFrameStarted();
  state.NotifyReadyToCommit();
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_COMMIT);
}

void TestForceCommitWhenReplacementActivationInProgress(
    bool main_frame_before_draw_enabled) {
  SchedulerSettings settings;
  settings.impl_side_painting = true;
  settings.main_frame_before_draw_enabled = main_frame_before_draw_enabled;
  StateMachine state(settings);
  state.SetCanStart();
  state.UpdateState(state.NextAction());
  state.CreateAndInitializeOutputSurfaceWithActivatedCommit();
  state.SetVisible(true);
  state.SetCanDraw(true);

  // Impl-side painting of replacement commit is in-progress.
  if (settings.main_frame_before_draw_enabled) {
    state.SetCommitState(
        SchedulerStateMachine::COMMIT_STATE_WAITING_FOR_ACTIVATION);
  } else {
    state.SetCommitState(
        SchedulerStateMachine::COMMIT_STATE_WAITING_FOR_FIRST_DRAW);
  }
  state.SetReadbackState(
      SchedulerStateMachine::READBACK_STATE_WAITING_FOR_REPLACEMENT_ACTIVATION);
  state.SetHasPendingTree(true);

  // Forced commit is requested during the impl-side painting.
  state.SetNeedsForcedCommitForReadback();
  EXPECT_FALSE(state.NeedsCommit());

  state.NotifyReadyToActivate();
  EXPECT_ACTION_UPDATE_STATE(
      SchedulerStateMachine::ACTION_ACTIVATE_PENDING_TREE);
  // New replacement commit is needed for incoming forced commit.
  EXPECT_EQ(SchedulerStateMachine::READBACK_STATE_NEEDS_BEGIN_MAIN_FRAME,
            state.readback_state());
  EXPECT_TRUE(state.NeedsCommit());
  if (settings.main_frame_before_draw_enabled) {
    // New replacement commit is scheduled.
    EXPECT_ACTION_UPDATE_STATE(
        SchedulerStateMachine::ACTION_SEND_BEGIN_MAIN_FRAME);
    // Forced commit is started.
    EXPECT_EQ(SchedulerStateMachine::READBACK_STATE_WAITING_FOR_COMMIT,
              state.readback_state());
  }
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);

  state.OnBeginImplFrame(BeginFrameArgs::CreateForTesting());
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
  // Perform the draw & swap of replacement commit.
  state.OnBeginImplFrameDeadline();
  EXPECT_ACTION_UPDATE_STATE(
      SchedulerStateMachine::ACTION_DRAW_AND_SWAP_IF_POSSIBLE);
  if (!settings.main_frame_before_draw_enabled) {
    // New replacement commit is scheduled.
    EXPECT_ACTION_UPDATE_STATE(
        SchedulerStateMachine::ACTION_SEND_BEGIN_MAIN_FRAME);
    // Forced commit is started.
    EXPECT_EQ(SchedulerStateMachine::READBACK_STATE_WAITING_FOR_COMMIT,
              state.readback_state());
  }
  EXPECT_ACTION_UPDATE_STATE(
      SchedulerStateMachine::ACTION_NONE);

  // Finish the forced commit and draw it.
  state.NotifyBeginMainFrameStarted();
  state.NotifyReadyToCommit();
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_COMMIT);
  state.NotifyReadyToActivate();
  EXPECT_ACTION_UPDATE_STATE(
      SchedulerStateMachine::ACTION_ACTIVATE_PENDING_TREE);
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_DRAW_AND_READBACK)
  EXPECT_EQ(
      SchedulerStateMachine::READBACK_STATE_WAITING_FOR_REPLACEMENT_COMMIT,
      state.readback_state());
  EXPECT_EQ(SchedulerStateMachine::COMMIT_STATE_BEGIN_MAIN_FRAME_SENT,
            state.CommitState());
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);

  // Finish the replacement commit and draw it.
  state.NotifyBeginMainFrameStarted();
  state.NotifyReadyToCommit();
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_COMMIT);
  state.NotifyReadyToActivate();
  EXPECT_ACTION_UPDATE_STATE(
      SchedulerStateMachine::ACTION_ACTIVATE_PENDING_TREE);
  state.OnBeginImplFrame(BeginFrameArgs::CreateForTesting());
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
  state.OnBeginImplFrameDeadline();
  EXPECT_ACTION_UPDATE_STATE(
      SchedulerStateMachine::ACTION_DRAW_AND_SWAP_IF_POSSIBLE);
  EXPECT_EQ(SchedulerStateMachine::READBACK_STATE_IDLE, state.readback_state());
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
}

// Explicitly test when main_frame_before_draw_enabled = true.
TEST(SchedulerStateMachineTest,
     ForceCommitWhenReplacementActivationInProgressAndMainFrameEnabled) {
  bool main_frame_before_draw_enabled = true;
  TestForceCommitWhenReplacementActivationInProgress(
      main_frame_before_draw_enabled);
}

// Explicitly test when main_frame_before_draw_enabled = false.
TEST(SchedulerStateMachineTest,
     ForceCommitWhenReplacementActivationInProgressAndMainFrameDisabled) {
  bool main_frame_before_draw_enabled = false;
  TestForceCommitWhenReplacementActivationInProgress(
      main_frame_before_draw_enabled);
}

// Test with main_frame_before_activation_enable = true;
TEST(SchedulerStateMachineTest,
     ForceCommitWhenReplacementActivationInProgressWithMFBA) {
  SchedulerSettings settings;
  settings.impl_side_painting = true;
  settings.main_frame_before_activation_enabled = true;
  StateMachine state(settings);
  state.SetCanStart();
  state.UpdateState(state.NextAction());
  state.CreateAndInitializeOutputSurfaceWithActivatedCommit();
  state.SetVisible(true);
  state.SetCanDraw(true);

  // When impl-side painting of replacement commit is in-progress, commit state
  // is idle because main_frame_before_activation is enabled.
  state.SetCommitState(
      SchedulerStateMachine::COMMIT_STATE_IDLE);
  state.SetReadbackState(
      SchedulerStateMachine::READBACK_STATE_WAITING_FOR_REPLACEMENT_ACTIVATION);
  state.SetHasPendingTree(true);

  // New commit is requested and scheduled when impl-side painting is in
  // progress.
  state.SetNeedsCommit();
  state.OnBeginImplFrame(BeginFrameArgs::CreateForTesting());
  EXPECT_ACTION_UPDATE_STATE(
      SchedulerStateMachine::ACTION_SEND_BEGIN_MAIN_FRAME);
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);

  // Forced commit is requested during the impl-side painting.
  state.SetNeedsForcedCommitForReadback();
  EXPECT_FALSE(state.NeedsCommit());

  state.OnBeginImplFrameDeadline();
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);

  state.NotifyReadyToActivate();
  EXPECT_ACTION_UPDATE_STATE(
      SchedulerStateMachine::ACTION_ACTIVATE_PENDING_TREE);
  // Replacement commit for requested forced commit is already scheduled.
  EXPECT_EQ(SchedulerStateMachine::READBACK_STATE_WAITING_FOR_COMMIT,
            state.readback_state());
  EXPECT_FALSE(state.NeedsCommit());
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);

  state.OnBeginImplFrame(BeginFrameArgs::CreateForTesting());
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
  // Perform the draw & swap of replacement commit.
  state.OnBeginImplFrameDeadline();
  EXPECT_ACTION_UPDATE_STATE(
      SchedulerStateMachine::ACTION_DRAW_AND_SWAP_IF_POSSIBLE);
  EXPECT_ACTION_UPDATE_STATE(
      SchedulerStateMachine::ACTION_NONE);

  // forced commit is started.
  state.NotifyBeginMainFrameStarted();
  state.NotifyReadyToCommit();
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_COMMIT);
}

TEST(SchedulerStateMachineTest, TestInitialActionsWhenContextLost) {
  SchedulerSettings default_scheduler_settings;
  StateMachine state(default_scheduler_settings);
  state.SetCanStart();
  state.UpdateState(state.NextAction());
  state.CreateAndInitializeOutputSurfaceWithActivatedCommit();
  state.SetVisible(true);
  state.SetCanDraw(true);
  state.SetNeedsCommit();
  state.DidLoseOutputSurface();

  // When we are visible, we normally want to begin output surface creation
  // as soon as possible.
  EXPECT_ACTION_UPDATE_STATE(
      SchedulerStateMachine::ACTION_BEGIN_OUTPUT_SURFACE_CREATION);

  state.DidCreateAndInitializeOutputSurface();
  EXPECT_EQ(state.output_surface_state(),
            SchedulerStateMachine::OUTPUT_SURFACE_WAITING_FOR_FIRST_COMMIT);

  // We should not send a BeginMainFrame when we are invisible, even if we've
  // lost the output surface and are trying to get the first commit, since the
  // main thread will just abort anyway.
  state.SetVisible(false);
  EXPECT_EQ(SchedulerStateMachine::ACTION_NONE, state.NextAction())
      << *state.AsValue();

  // If there is a forced commit, however, we could be blocking a readback
  // on the main thread, so we need to unblock it before we can get our
  // output surface, even if we are not visible.
  state.SetNeedsForcedCommitForReadback();
  EXPECT_EQ(
      SchedulerStateMachine::ACTION_SEND_BEGIN_MAIN_FRAME, state.NextAction())
      << *state.AsValue();
}

TEST(SchedulerStateMachineTest, TestImmediateFinishCommit) {
  SchedulerSettings default_scheduler_settings;
  StateMachine state(default_scheduler_settings);
  state.SetCanStart();
  state.UpdateState(state.NextAction());
  state.CreateAndInitializeOutputSurfaceWithActivatedCommit();
  state.SetVisible(true);
  state.SetCanDraw(true);

  // Schedule a readback, commit it, draw it.
  state.SetNeedsForcedCommitForReadback();
  EXPECT_ACTION_UPDATE_STATE(
      SchedulerStateMachine::ACTION_SEND_BEGIN_MAIN_FRAME);

  state.NotifyBeginMainFrameStarted();
  state.NotifyReadyToCommit();

  EXPECT_EQ(SchedulerStateMachine::COMMIT_STATE_READY_TO_COMMIT,
            state.CommitState());
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_COMMIT);

  EXPECT_TRUE(state.active_tree_needs_first_draw());

  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_DRAW_AND_READBACK);
  state.DidDrawIfPossibleCompleted(DrawSwapReadbackResult::DRAW_SUCCESS);

  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);

  // Should be waiting for the normal BeginMainFrame.
  EXPECT_EQ(SchedulerStateMachine::COMMIT_STATE_BEGIN_MAIN_FRAME_SENT,
            state.CommitState());
}

TEST(SchedulerStateMachineTest, TestImmediateFinishCommitDuringCommit) {
  SchedulerSettings scheduler_settings;
  StateMachine state(scheduler_settings);
  state.SetCanStart();
  state.UpdateState(state.NextAction());
  state.CreateAndInitializeOutputSurfaceWithActivatedCommit();
  state.SetVisible(true);
  state.SetCanDraw(true);

  // Start a normal commit.
  state.SetNeedsCommit();
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);

  // Schedule a readback, commit it, draw it.
  state.SetNeedsForcedCommitForReadback();
  EXPECT_ACTION_UPDATE_STATE(
      SchedulerStateMachine::ACTION_SEND_BEGIN_MAIN_FRAME);
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
  state.NotifyBeginMainFrameStarted();
  state.NotifyReadyToCommit();
  EXPECT_EQ(SchedulerStateMachine::COMMIT_STATE_READY_TO_COMMIT,
            state.CommitState());
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_COMMIT);

  EXPECT_TRUE(state.active_tree_needs_first_draw());

  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_DRAW_AND_READBACK);
  state.DidDrawIfPossibleCompleted(DrawSwapReadbackResult::DRAW_SUCCESS);
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);

  // Should be waiting for the normal BeginMainFrame.
  EXPECT_EQ(SchedulerStateMachine::COMMIT_STATE_BEGIN_MAIN_FRAME_SENT,
            state.CommitState())
      << *state.AsValue();
}

TEST(SchedulerStateMachineTest, ImmediateBeginMainFrameAbortedWhileInvisible) {
  SchedulerSettings scheduler_settings;
  StateMachine state(scheduler_settings);
  state.SetCanStart();
  state.UpdateState(state.NextAction());
  state.CreateAndInitializeOutputSurfaceWithActivatedCommit();
  state.SetVisible(true);
  state.SetCanDraw(true);

  state.SetNeedsCommit();
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);

  state.SetNeedsForcedCommitForReadback();
  EXPECT_ACTION_UPDATE_STATE(
      SchedulerStateMachine::ACTION_SEND_BEGIN_MAIN_FRAME);
  state.NotifyBeginMainFrameStarted();
  state.NotifyReadyToCommit();

  EXPECT_EQ(SchedulerStateMachine::COMMIT_STATE_READY_TO_COMMIT,
            state.CommitState());
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_COMMIT);

  EXPECT_TRUE(state.active_tree_needs_first_draw());

  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_DRAW_AND_READBACK);
  state.DidDrawIfPossibleCompleted(DrawSwapReadbackResult::DRAW_SUCCESS);
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);

  // Should be waiting for BeginMainFrame.
  EXPECT_EQ(SchedulerStateMachine::COMMIT_STATE_BEGIN_MAIN_FRAME_SENT,
            state.CommitState())
      << *state.AsValue();

  // Become invisible and abort BeginMainFrame.
  state.SetVisible(false);
  state.BeginMainFrameAborted(false);

  // Should be back in the idle state, but needing a commit.
  EXPECT_EQ(SchedulerStateMachine::COMMIT_STATE_IDLE, state.CommitState());
  EXPECT_TRUE(state.NeedsCommit());
}

TEST(SchedulerStateMachineTest, ImmediateFinishCommitWhileCantDraw) {
  SchedulerSettings default_scheduler_settings;
  StateMachine state(default_scheduler_settings);
  state.SetCanStart();
  state.UpdateState(state.NextAction());
  state.CreateAndInitializeOutputSurfaceWithActivatedCommit();
  state.SetVisible(true);
  state.SetCanDraw(false);

  state.SetNeedsCommit();
  state.UpdateState(state.NextAction());

  state.SetNeedsForcedCommitForReadback();
  state.UpdateState(state.NextAction());
  state.NotifyBeginMainFrameStarted();
  state.NotifyReadyToCommit();

  EXPECT_EQ(SchedulerStateMachine::COMMIT_STATE_READY_TO_COMMIT,
            state.CommitState());
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_COMMIT);

  EXPECT_TRUE(state.active_tree_needs_first_draw());

  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_DRAW_AND_READBACK);
  state.DidDrawIfPossibleCompleted(DrawSwapReadbackResult::DRAW_SUCCESS);
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
}

TEST(SchedulerStateMachineTest, ReportIfNotDrawing) {
  SchedulerSettings default_scheduler_settings;
  StateMachine state(default_scheduler_settings);
  state.SetCanStart();
  state.UpdateState(state.NextAction());
  state.CreateAndInitializeOutputSurfaceWithActivatedCommit();

  state.SetCanDraw(true);
  state.SetVisible(true);
  EXPECT_FALSE(state.PendingDrawsShouldBeAborted());

  state.SetCanDraw(false);
  state.SetVisible(true);
  EXPECT_TRUE(state.PendingDrawsShouldBeAborted());

  state.SetCanDraw(true);
  state.SetVisible(false);
  EXPECT_TRUE(state.PendingDrawsShouldBeAborted());

  state.SetCanDraw(false);
  state.SetVisible(false);
  EXPECT_TRUE(state.PendingDrawsShouldBeAborted());

  state.SetCanDraw(true);
  state.SetVisible(true);
  EXPECT_FALSE(state.PendingDrawsShouldBeAborted());
}

TEST(SchedulerStateMachineTest, ReportIfNotDrawingFromAcquiredTextures) {
  SchedulerSettings default_scheduler_settings;
  StateMachine state(default_scheduler_settings);
  state.SetCanStart();
  state.UpdateState(state.NextAction());
  state.CreateAndInitializeOutputSurfaceWithActivatedCommit();
  state.SetCanDraw(true);
  state.SetVisible(true);
  EXPECT_FALSE(state.PendingDrawsShouldBeAborted());

  state.SetMainThreadNeedsLayerTextures();
  EXPECT_ACTION_UPDATE_STATE(
      SchedulerStateMachine::ACTION_ACQUIRE_LAYER_TEXTURES_FOR_MAIN_THREAD);
  EXPECT_TRUE(state.PendingDrawsShouldBeAborted());

  state.SetNeedsCommit();
  state.OnBeginImplFrame(BeginFrameArgs::CreateForTesting());
  EXPECT_ACTION_UPDATE_STATE(
      SchedulerStateMachine::ACTION_SEND_BEGIN_MAIN_FRAME);
  EXPECT_TRUE(state.PendingDrawsShouldBeAborted());

  EXPECT_EQ(SchedulerStateMachine::ACTION_NONE, state.NextAction());

  state.NotifyBeginMainFrameStarted();
  state.NotifyReadyToCommit();
  EXPECT_TRUE(state.PendingDrawsShouldBeAborted());

  EXPECT_EQ(SchedulerStateMachine::ACTION_COMMIT, state.NextAction());

  state.UpdateState(state.NextAction());
  EXPECT_FALSE(state.PendingDrawsShouldBeAborted());
}

TEST(SchedulerStateMachineTest, AcquireTexturesWithAbort) {
  SchedulerSettings default_scheduler_settings;
  StateMachine state(default_scheduler_settings);
  state.SetCanStart();
  state.UpdateState(state.NextAction());
  state.DidCreateAndInitializeOutputSurface();
  state.SetCanDraw(true);
  state.SetVisible(true);

  state.SetMainThreadNeedsLayerTextures();
  EXPECT_EQ(
      SchedulerStateMachine::ACTION_ACQUIRE_LAYER_TEXTURES_FOR_MAIN_THREAD,
      state.NextAction());
  state.UpdateState(state.NextAction());
  EXPECT_TRUE(state.PendingDrawsShouldBeAborted());

  EXPECT_EQ(SchedulerStateMachine::ACTION_NONE, state.NextAction());

  state.SetNeedsCommit();
  EXPECT_EQ(SchedulerStateMachine::ACTION_SEND_BEGIN_MAIN_FRAME,
            state.NextAction());
  state.UpdateState(state.NextAction());
  EXPECT_TRUE(state.PendingDrawsShouldBeAborted());

  EXPECT_EQ(SchedulerStateMachine::ACTION_NONE, state.NextAction());

  state.BeginMainFrameAborted(true);

  EXPECT_EQ(SchedulerStateMachine::ACTION_NONE, state.NextAction());
  EXPECT_FALSE(state.PendingDrawsShouldBeAborted());
}

TEST(SchedulerStateMachineTest, TestTriggerDeadlineEarlyAfterAbortedCommit) {
  SchedulerSettings settings;
  settings.impl_side_painting = true;
  StateMachine state(settings);
  state.SetCanStart();
  state.UpdateState(state.NextAction());
  state.CreateAndInitializeOutputSurfaceWithActivatedCommit();
  state.SetVisible(true);
  state.SetCanDraw(true);

  // This test mirrors what happens during the first frame of a scroll gesture.
  // First we get the input event and a BeginFrame.
  state.OnBeginImplFrame(BeginFrameArgs::CreateForTesting());

  // As a response the compositor requests a redraw and a commit to tell the
  // main thread about the new scroll offset.
  state.SetNeedsRedraw(true);
  state.SetNeedsCommit();

  // We should start the commit normally.
  EXPECT_ACTION_UPDATE_STATE(
      SchedulerStateMachine::ACTION_SEND_BEGIN_MAIN_FRAME);
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);

  // Since only the scroll offset changed, the main thread will abort the
  // commit.
  state.BeginMainFrameAborted(true);

  // Since the commit was aborted, we should draw right away instead of waiting
  // for the deadline.
  EXPECT_TRUE(state.ShouldTriggerBeginImplFrameDeadlineEarly());
}

TEST(SchedulerStateMachineTest, TestTriggerDeadlineEarlyForSmoothness) {
  SchedulerSettings settings;
  settings.impl_side_painting = true;
  StateMachine state(settings);
  state.SetCanStart();
  state.UpdateState(state.NextAction());
  state.CreateAndInitializeOutputSurfaceWithActivatedCommit();
  state.SetVisible(true);
  state.SetCanDraw(true);

  // This test ensures that impl-draws are prioritized over main thread updates
  // in prefer smoothness mode.
  state.OnBeginImplFrame(BeginFrameArgs::CreateForTesting());
  state.SetNeedsRedraw(true);
  state.SetNeedsCommit();
  EXPECT_ACTION_UPDATE_STATE(
      SchedulerStateMachine::ACTION_SEND_BEGIN_MAIN_FRAME);
  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);

  // The deadline is not triggered early until we enter prefer smoothness mode.
  EXPECT_FALSE(state.ShouldTriggerBeginImplFrameDeadlineEarly());
  state.SetSmoothnessTakesPriority(true);
  EXPECT_TRUE(state.ShouldTriggerBeginImplFrameDeadlineEarly());
}

}  // namespace
}  // namespace cc