cc: Single-threaded impl-side painting for unit tests

cc/trees/single_thread_proxy.cc

 // 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/trees/single_thread_proxy.h"
 
 #include "base/auto_reset.h"
 #include "base/debug/trace_event.h"
 #include "cc/debug/benchmark_instrumentation.h"
 #include "cc/output/context_provider.h"
 #include "cc/output/output_surface.h"
 #include "cc/quads/draw_quad.h"
 #include "cc/resources/prioritized_resource_manager.h"
 #include "cc/resources/resource_update_controller.h"
-#include "cc/trees/blocking_task_runner.h"
 #include "cc/trees/layer_tree_host.h"
 #include "cc/trees/layer_tree_host_single_thread_client.h"
 #include "cc/trees/layer_tree_impl.h"
 #include "cc/trees/scoped_abort_remaining_swap_promises.h"
 #include "ui/gfx/frame_time.h"
 
 namespace cc {
 
 scoped_ptr<Proxy> SingleThreadProxy::Create(
     LayerTreeHost* layer_tree_host,
@@ skipping 13 matching lines @@
       timing_history_(layer_tree_host->rendering_stats_instrumentation()),
       next_frame_is_newly_committed_frame_(false),
       inside_draw_(false),
       defer_commits_(false),
       commit_was_deferred_(false),
       commit_requested_(false),
       weak_factory_(this) {
   TRACE_EVENT0("cc", "SingleThreadProxy::SingleThreadProxy");
   DCHECK(Proxy::IsMainThread());
   DCHECK(layer_tree_host);
-
-  // Impl-side painting not supported without threaded compositing.
-  CHECK(!layer_tree_host->settings().impl_side_painting)
-      << "Threaded compositing must be enabled to use impl-side painting.";
 }
 
 void SingleThreadProxy::Start() {
   DebugScopedSetImplThread impl(this);
   layer_tree_host_impl_ = layer_tree_host_->CreateLayerTreeHostImpl(this);
 }
 
 SingleThreadProxy::~SingleThreadProxy() {
   TRACE_EVENT0("cc", "SingleThreadProxy::~SingleThreadProxy");
   DCHECK(Proxy::IsMainThread());
@@ skipping 89 matching lines @@
   client_->ScheduleAnimation();
   SetNeedsCommit();
 }
 
 void SingleThreadProxy::SetNeedsUpdateLayers() {
   TRACE_EVENT0("cc", "SingleThreadProxy::SetNeedsUpdateLayers");
   DCHECK(Proxy::IsMainThread());
   SetNeedsCommit();
 }
 
-void SingleThreadProxy::DoCommit(const BeginFrameArgs& begin_frame_args) {
+void SingleThreadProxy::DoCommit() {
   TRACE_EVENT0("cc", "SingleThreadProxy::DoCommit");
   DCHECK(Proxy::IsMainThread());
-  layer_tree_host_->WillBeginMainFrame();
-  layer_tree_host_->BeginMainFrame(begin_frame_args);
-  layer_tree_host_->AnimateLayers(begin_frame_args.frame_time);
-  layer_tree_host_->Layout();
+
   commit_requested_ = false;
-
-  if (PrioritizedResourceManager* contents_texture_manager =
-          layer_tree_host_->contents_texture_manager()) {
-    contents_texture_manager->UnlinkAndClearEvictedBackings();
-    contents_texture_manager->SetMaxMemoryLimitBytes(
-        layer_tree_host_impl_->memory_allocation_limit_bytes());
-    contents_texture_manager->SetExternalPriorityCutoff(
-        layer_tree_host_impl_->memory_allocation_priority_cutoff());
-  }
-
-  scoped_ptr<ResourceUpdateQueue> queue =
-      make_scoped_ptr(new ResourceUpdateQueue);
-
-  layer_tree_host_->UpdateLayers(queue.get());
-
   layer_tree_host_->WillCommit();
 
   // Commit immediately.
   {
     DebugScopedSetMainThreadBlocked main_thread_blocked(this);
     DebugScopedSetImplThread impl(this);
 
     // This CapturePostTasks should be destroyed before CommitComplete() is
     // called since that goes out to the embedder, and we want the embedder
     // to receive its callbacks before that.
-    BlockingTaskRunner::CapturePostTasks blocked(
-        blocking_main_thread_task_runner());
+    commit_blocking_task_runner_.reset(new BlockingTaskRunner::CapturePostTasks(
+        blocking_main_thread_task_runner()));
 
     layer_tree_host_impl_->BeginCommit();
 
     if (PrioritizedResourceManager* contents_texture_manager =
         layer_tree_host_->contents_texture_manager()) {
       contents_texture_manager->PushTexturePrioritiesToBackings();
     }
     layer_tree_host_->BeginCommitOnImplThread(layer_tree_host_impl_.get());
 
     scoped_ptr<ResourceUpdateController> update_controller =
         ResourceUpdateController::Create(
             NULL,
             MainThreadTaskRunner(),
-            queue.Pass(),
+            queue_for_commit_.Pass(),
             layer_tree_host_impl_->resource_provider());
     update_controller->Finalize();
 
     if (layer_tree_host_impl_->EvictedUIResourcesExist())
       layer_tree_host_->RecreateUIResources();
 
     layer_tree_host_->FinishCommitOnImplThread(layer_tree_host_impl_.get());
 
     layer_tree_host_impl_->CommitComplete();
 
     UpdateBackgroundAnimateTicking();
 
 #if DCHECK_IS_ON
     // In the single-threaded case, the scale and scroll deltas should never be
     // touched on the impl layer tree.
     scoped_ptr<ScrollAndScaleSet> scroll_info =
         layer_tree_host_impl_->ProcessScrollDeltas();
     DCHECK(!scroll_info->scrolls.size());
     DCHECK_EQ(1.f, scroll_info->page_scale_delta);
 #endif
 
     RenderingStatsInstrumentation* stats_instrumentation =
         layer_tree_host_->rendering_stats_instrumentation();
     benchmark_instrumentation::IssueMainThreadRenderingStatsEvent(
         stats_instrumentation->main_thread_rendering_stats());
     stats_instrumentation->AccumulateAndClearMainThreadStats();
   }
+
+  if (layer_tree_host_->settings().impl_side_painting) {
+    // TODO(enne): just commit directly to the active tree.
+    //
+    // Synchronously activate during commit to satisfy any potential
+    // SetNextCommitWaitsForActivation calls.  Unfortunately, the tree
+    // might not be ready to draw, so DidActivateSyncTree must set
+    // the flag to force the tree to not draw until textures are ready.
+    NotifyReadyToActivate();
+  } else {
+    CommitComplete();
+  }
+}
+
+void SingleThreadProxy::CommitComplete() {
+  DCHECK(!layer_tree_host_impl_->pending_tree())
+      << "Activation is expected to have synchronously occurred by now.";
+  DCHECK(commit_blocking_task_runner_);
+
+  DebugScopedSetMainThread main(this);
+  commit_blocking_task_runner_.reset();
   layer_tree_host_->CommitComplete();
   layer_tree_host_->DidBeginMainFrame();
   timing_history_.DidCommit();
 
   next_frame_is_newly_committed_frame_ = true;
 }
 
 void SingleThreadProxy::SetNeedsCommit() {
   DCHECK(Proxy::IsMainThread());
   DebugScopedSetImplThread impl(this);
   client_->ScheduleComposite();
   if (scheduler_on_impl_thread_)
     scheduler_on_impl_thread_->SetNeedsCommit();
   commit_requested_ = true;
 }
 
 void SingleThreadProxy::SetNeedsRedraw(const gfx::Rect& damage_rect) {
   TRACE_EVENT0("cc", "SingleThreadProxy::SetNeedsRedraw");
   DCHECK(Proxy::IsMainThread());
   DebugScopedSetImplThread impl(this);
   client_->ScheduleComposite();
   SetNeedsRedrawRectOnImplThread(damage_rect);
 }
 
 void SingleThreadProxy::SetNextCommitWaitsForActivation() {
-  // There is no activation here other than commit. So do nothing.
+  // Activation always forced in commit, so nothing to do.
   DCHECK(Proxy::IsMainThread());
 }
 
 void SingleThreadProxy::SetDeferCommits(bool defer_commits) {
   DCHECK(Proxy::IsMainThread());
   // Deferring commits only makes sense if there's a scheduler.
   if (!scheduler_on_impl_thread_)
     return;
   if (defer_commits_ == defer_commits)
     return;
@@ skipping 48 matching lines @@
 void SingleThreadProxy::OnCanDrawStateChanged(bool can_draw) {
   TRACE_EVENT1(
       "cc", "SingleThreadProxy::OnCanDrawStateChanged", "can_draw", can_draw);
   DCHECK(Proxy::IsImplThread());
   UpdateBackgroundAnimateTicking();
   if (scheduler_on_impl_thread_)
     scheduler_on_impl_thread_->SetCanDraw(can_draw);
 }
 
 void SingleThreadProxy::NotifyReadyToActivate() {
-  // Impl-side painting only.
-  NOTREACHED();
+  TRACE_EVENT0("cc", "SingleThreadProxy::NotifyReadyToActivate");
+  DebugScopedSetImplThread impl(this);
+  if (scheduler_on_impl_thread_)
+    scheduler_on_impl_thread_->NotifyReadyToActivate();
 }
 
 void SingleThreadProxy::SetNeedsRedrawOnImplThread() {
   client_->ScheduleComposite();
   if (scheduler_on_impl_thread_)
     scheduler_on_impl_thread_->SetNeedsRedraw();
 }
 
 void SingleThreadProxy::SetNeedsAnimateOnImplThread() {
   SetNeedsRedrawOnImplThread();
 }
 
 void SingleThreadProxy::SetNeedsManageTilesOnImplThread() {
-  // Impl-side painting only.
-  NOTREACHED();
+  TRACE_EVENT0("cc", "SingleThreadProxy::SetNeedsManageTilesOnImplThread");
+  if (scheduler_on_impl_thread_)
+    scheduler_on_impl_thread_->SetNeedsManageTiles();
 }
 
 void SingleThreadProxy::SetNeedsRedrawRectOnImplThread(
     const gfx::Rect& damage_rect) {
   layer_tree_host_impl_->SetViewportDamage(damage_rect);
   SetNeedsRedrawOnImplThread();
 }
 
 void SingleThreadProxy::DidInitializeVisibleTileOnImplThread() {
-  // Impl-side painting only.
-  NOTREACHED();
+  TRACE_EVENT0("cc", "SingleThreadProxy::DidInitializeVisibleTileOnImplThread");
+  if (scheduler_on_impl_thread_)
+    scheduler_on_impl_thread_->SetNeedsRedraw();
 }
 
 void SingleThreadProxy::SetNeedsCommitOnImplThread() {
   client_->ScheduleComposite();
   if (scheduler_on_impl_thread_)
     scheduler_on_impl_thread_->SetNeedsCommit();
 }
 
 void SingleThreadProxy::PostAnimationEventsToMainThreadOnImplThread(
     scoped_ptr<AnimationEventsVector> events) {
@@ skipping 16 matching lines @@
 
   if (!contents_texture_manager || !resource_provider)
     return false;
 
   return contents_texture_manager->ReduceMemoryOnImplThread(
       limit_bytes, priority_cutoff, resource_provider);
 }
 
 bool SingleThreadProxy::IsInsideDraw() { return inside_draw_; }
 
+void SingleThreadProxy::DidActivateSyncTree() {
+  // Non-impl-side painting finishes commit in DoCommit.  Impl-side painting
+  // defers until here to simulate SetNextCommitWaitsForActivation.
+  if (layer_tree_host_impl_->settings().impl_side_painting) {
+    // This is required because NotifyReadyToActivate gets called when
+    // the pending tree is not actually ready in the SingleThreadProxy.
+    layer_tree_host_impl_->active_tree()->SetRequiresHighResToDraw();
+
+    // Since activation could cause tasks to run, post CommitComplete
+    // separately so that it runs after these tasks.  This is the loose
+    // equivalent of blocking commit until activation and also running
+    // all tasks posted during commit/activation before CommitComplete.
+    MainThreadTaskRunner()->PostTask(
+        FROM_HERE,
+        base::Bind(&SingleThreadProxy::CommitComplete,
+                   weak_factory_.GetWeakPtr()));
+  }
+
+  UpdateBackgroundAnimateTicking();
+  timing_history_.DidActivateSyncTree();
+}
+
+void SingleThreadProxy::DidManageTiles() {
+  DCHECK(layer_tree_host_impl_->settings().impl_side_painting);
+  DCHECK(Proxy::IsImplThread());
+  if (scheduler_on_impl_thread_)
+    scheduler_on_impl_thread_->DidManageTiles();
+}
+
 void SingleThreadProxy::UpdateRendererCapabilitiesOnImplThread() {
   DCHECK(IsImplThread());
   renderer_capabilities_for_main_thread_ =
       layer_tree_host_impl_->GetRendererCapabilities().MainThreadCapabilities();
 }
 
-void SingleThreadProxy::DidManageTiles() {
-  // Impl-side painting only.
-  NOTREACHED();
-}
-
 void SingleThreadProxy::DidLoseOutputSurfaceOnImplThread() {
   TRACE_EVENT0("cc", "SingleThreadProxy::DidLoseOutputSurfaceOnImplThread");
   {
     DebugScopedSetMainThread main(this);
     // This must happen before we notify the scheduler as it may try to recreate
     // the output surface if already in BEGIN_IMPL_FRAME_STATE_IDLE.
     layer_tree_host_->DidLoseOutputSurface();
   }
   client_->DidAbortSwapBuffers();
   if (scheduler_on_impl_thread_)
@@ skipping 11 matching lines @@
   TRACE_EVENT0("cc", "SingleThreadProxy::DidSwapBuffersCompleteOnImplThread");
   if (scheduler_on_impl_thread_)
     scheduler_on_impl_thread_->DidSwapBuffersComplete();
   layer_tree_host_->DidCompleteSwapBuffers();
 }
 
 void SingleThreadProxy::CompositeImmediately(base::TimeTicks frame_begin_time) {
   TRACE_EVENT0("cc", "SingleThreadProxy::CompositeImmediately");
   DCHECK(Proxy::IsMainThread());
   DCHECK(!layer_tree_host_->output_surface_lost());
+  DCHECK(!layer_tree_host_impl_->settings().impl_side_painting)
+      << "Impl-side painting and synchronous compositing are not supported.";
 
-  BeginFrameArgs begin_frame_args = BeginFrameArgs::Create(
-      frame_begin_time, base::TimeTicks(), BeginFrameArgs::DefaultInterval());
-  DoCommit(begin_frame_args);
+  ScopedAbortRemainingSwapPromises swap_promise_checker(layer_tree_host_);

[danakj, 2014/10/02 17:15:54]

do you think we should unit test this?

+
+  BeginFrameArgs begin_frame_args(BeginFrameArgs::Create(
+      frame_begin_time, base::TimeTicks(), BeginFrameArgs::DefaultInterval()));
+  DoBeginMainFrame(begin_frame_args);
+  DoCommit();
 
   LayerTreeHostImpl::FrameData frame;
   DoComposite(frame_begin_time, &frame);
 }
 
 void SingleThreadProxy::AsValueInto(base::debug::TracedValue* state) const {
   // The following line casts away const modifiers because it is just
   // setting debug state. We still want the AsValue() function and its
   // call chain to be const throughout.
   DebugScopedSetImplThread impl(const_cast<SingleThreadProxy*>(this));
@@ skipping 27 matching lines @@
   DCHECK(Proxy::IsImplThread());
   layer_tree_host_impl_->UpdateBackgroundAnimateTicking(
       !ShouldComposite() && layer_tree_host_impl_->active_tree()->root_layer());
 }
 
 DrawResult SingleThreadProxy::DoComposite(base::TimeTicks frame_begin_time,
                                           LayerTreeHostImpl::FrameData* frame) {
   TRACE_EVENT0("cc", "SingleThreadProxy::DoComposite");
   DCHECK(!layer_tree_host_->output_surface_lost());
 
+  DrawResult draw_result;
+  bool draw_frame;
   {
     DebugScopedSetImplThread impl(this);
     base::AutoReset<bool> mark_inside(&inside_draw_, true);
 
     // We guard PrepareToDraw() with CanDraw() because it always returns a valid
     // frame, so can only be used when such a frame is possible. Since
     // DrawLayers() depends on the result of PrepareToDraw(), it is guarded on
     // CanDraw() as well.
     if (!ShouldComposite()) {
       UpdateBackgroundAnimateTicking();
       return DRAW_ABORTED_CANT_DRAW;
     }
 
     timing_history_.DidStartDrawing();
 
     layer_tree_host_impl_->Animate(
         layer_tree_host_impl_->CurrentBeginFrameArgs().frame_time);
     UpdateBackgroundAnimateTicking();
 
-    layer_tree_host_impl_->PrepareToDraw(frame);
-    layer_tree_host_impl_->DrawLayers(frame, frame_begin_time);
+    draw_result = layer_tree_host_impl_->PrepareToDraw(frame);
+    draw_frame = draw_result == DRAW_SUCCESS;
+    if (draw_frame)
+      layer_tree_host_impl_->DrawLayers(frame, frame_begin_time);
     layer_tree_host_impl_->DidDrawAllLayers(*frame);
 
-    bool start_ready_animations = true;
+    bool start_ready_animations = draw_frame;
     layer_tree_host_impl_->UpdateAnimationState(start_ready_animations);
-
     layer_tree_host_impl_->ResetCurrentBeginFrameArgsForNextFrame();
 
     timing_history_.DidFinishDrawing();
   }
 
-  {
+  if (draw_frame) {
     DebugScopedSetImplThread impl(this);
 
     // This CapturePostTasks should be destroyed before
     // DidCommitAndDrawFrame() is called since that goes out to the
     // embedder,
     // and we want the embedder to receive its callbacks before that.
     // NOTE: This maintains consistent ordering with the ThreadProxy since
     // the DidCommitAndDrawFrame() must be post-tasked from the impl thread
     // there as the main thread is not blocked, so any posted tasks inside
     // the swap buffers will execute first.
     DebugScopedSetMainThreadBlocked main_thread_blocked(this);
 
     BlockingTaskRunner::CapturePostTasks blocked(
         blocking_main_thread_task_runner());
     layer_tree_host_impl_->SwapBuffers(*frame);
   }
   DidCommitAndDrawFrame();
 
-  return DRAW_SUCCESS;
+  return draw_result;
 }
 
 void SingleThreadProxy::DidCommitAndDrawFrame() {
   if (next_frame_is_newly_committed_frame_) {
     DebugScopedSetMainThread main(this);
     next_frame_is_newly_committed_frame_ = false;
     layer_tree_host_->DidCommitAndDrawFrame();
   }
 }
 
@@ skipping 25 matching lines @@
 }
 
 void SingleThreadProxy::BeginMainFrame() {
   if (defer_commits_) {
     DCHECK(!commit_was_deferred_);
     commit_was_deferred_ = true;
     layer_tree_host_->DidDeferCommit();
     return;
   }
 
-  // This checker assumes NotifyReadyToCommit below causes a synchronous commit.
+  // This checker assumes NotifyReadyToCommit in this stack causes a synchronous
+  // commit.
   ScopedAbortRemainingSwapPromises swap_promise_checker(layer_tree_host_);
 
   if (!layer_tree_host_->visible()) {
     TRACE_EVENT_INSTANT0("cc", "EarlyOut_NotVisible", TRACE_EVENT_SCOPE_THREAD);
     BeginMainFrameAbortedOnImplThread();
     return;
   }
 
   if (layer_tree_host_->output_surface_lost()) {
     TRACE_EVENT_INSTANT0(
         "cc", "EarlyOut_OutputSurfaceLost", TRACE_EVENT_SCOPE_THREAD);
     BeginMainFrameAbortedOnImplThread();
     return;
   }
 
+  const BeginFrameArgs& begin_frame_args =
+      layer_tree_host_impl_->CurrentBeginFrameArgs();
+  DoBeginMainFrame(begin_frame_args);
+}
+
+void SingleThreadProxy::DoBeginMainFrame(
+    const BeginFrameArgs& begin_frame_args) {
+  layer_tree_host_->WillBeginMainFrame();
+  layer_tree_host_->BeginMainFrame(begin_frame_args);
+  layer_tree_host_->AnimateLayers(begin_frame_args.frame_time);
+  layer_tree_host_->Layout();
+
+  if (PrioritizedResourceManager* contents_texture_manager =
+          layer_tree_host_->contents_texture_manager()) {
+    contents_texture_manager->UnlinkAndClearEvictedBackings();
+    contents_texture_manager->SetMaxMemoryLimitBytes(
+        layer_tree_host_impl_->memory_allocation_limit_bytes());
+    contents_texture_manager->SetExternalPriorityCutoff(
+        layer_tree_host_impl_->memory_allocation_priority_cutoff());
+  }
+
+  DCHECK(!queue_for_commit_);
+  queue_for_commit_ = make_scoped_ptr(new ResourceUpdateQueue);
+
+  layer_tree_host_->UpdateLayers(queue_for_commit_.get());
+
   timing_history_.DidBeginMainFrame();
 
-  DCHECK(scheduler_on_impl_thread_);
-  scheduler_on_impl_thread_->NotifyBeginMainFrameStarted();
-  scheduler_on_impl_thread_->NotifyReadyToCommit();
+  if (scheduler_on_impl_thread_) {
+    scheduler_on_impl_thread_->NotifyBeginMainFrameStarted();
+    scheduler_on_impl_thread_->NotifyReadyToCommit();
+  }
 }
 
 void SingleThreadProxy::BeginMainFrameAbortedOnImplThread() {
   DebugScopedSetImplThread impl(this);
   DCHECK(scheduler_on_impl_thread_->CommitPending());
   DCHECK(!layer_tree_host_impl_->pending_tree());
 
   // TODO(enne): SingleThreadProxy does not support cancelling commits yet so
   // did_handle is always false.
   bool did_handle = false;
   layer_tree_host_impl_->BeginMainFrameAborted(did_handle);
   scheduler_on_impl_thread_->BeginMainFrameAborted(did_handle);
 }
 
 DrawResult SingleThreadProxy::ScheduledActionDrawAndSwapIfPossible() {
   DebugScopedSetImplThread impl(this);
   LayerTreeHostImpl::FrameData frame;
   return DoComposite(layer_tree_host_impl_->CurrentBeginFrameArgs().frame_time,
                      &frame);
 }
 
 DrawResult SingleThreadProxy::ScheduledActionDrawAndSwapForced() {
   NOTREACHED();
   return INVALID_RESULT;
 }
 
 void SingleThreadProxy::ScheduledActionCommit() {
   DebugScopedSetMainThread main(this);
-  DoCommit(layer_tree_host_impl_->CurrentBeginFrameArgs());
+  DoCommit();
 }
 
 void SingleThreadProxy::ScheduledActionAnimate() {
   TRACE_EVENT0("cc", "ScheduledActionAnimate");
   layer_tree_host_impl_->Animate(
       layer_tree_host_impl_->CurrentBeginFrameArgs().frame_time);
 }
 
 void SingleThreadProxy::ScheduledActionUpdateVisibleTiles() {
-  // Impl-side painting only.
-  NOTREACHED();
+  DebugScopedSetImplThread impl(this);
+  layer_tree_host_impl_->UpdateVisibleTiles();
 }
 
 void SingleThreadProxy::ScheduledActionActivateSyncTree() {
+  DebugScopedSetImplThread impl(this);
+  layer_tree_host_impl_->ActivateSyncTree();
 }
 
 void SingleThreadProxy::ScheduledActionBeginOutputSurfaceCreation() {
   DebugScopedSetMainThread main(this);
   DCHECK(scheduler_on_impl_thread_);
   // If possible, create the output surface in a post task.  Synchronously
   // creating the output surface makes tests more awkward since this differs
   // from the ThreadProxy behavior.  However, sometimes there is no
   // task runner.
   if (Proxy::MainThreadTaskRunner()) {
     MainThreadTaskRunner()->PostTask(
         FROM_HERE,
         base::Bind(&SingleThreadProxy::RequestNewOutputSurface,
                    weak_factory_.GetWeakPtr()));
   } else {
     RequestNewOutputSurface();
   }
 }
 
 void SingleThreadProxy::ScheduledActionManageTiles() {
-  // Impl-side painting only.
-  NOTREACHED();
+  TRACE_EVENT0("cc", "SingleThreadProxy::ScheduledActionManageTiles");
+  DCHECK(layer_tree_host_impl_->settings().impl_side_painting);
+  DebugScopedSetImplThread impl(this);
+  layer_tree_host_impl_->ManageTiles();
 }
 
 void SingleThreadProxy::DidAnticipatedDrawTimeChange(base::TimeTicks time) {
 }
 
 base::TimeDelta SingleThreadProxy::DrawDurationEstimate() {
   return timing_history_.DrawDurationEstimate();
 }
 
 base::TimeDelta SingleThreadProxy::BeginMainFrameToCommitDurationEstimate() {
   return timing_history_.BeginMainFrameToCommitDurationEstimate();
 }
 
 base::TimeDelta SingleThreadProxy::CommitToActivateDurationEstimate() {
   return timing_history_.CommitToActivateDurationEstimate();
 }
 
 void SingleThreadProxy::DidBeginImplFrameDeadline() {
   layer_tree_host_impl_->ResetCurrentBeginFrameArgsForNextFrame();
 }
 
 }  // namespace cc