Update from https://crrev.com/314320

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 "base/trace_event/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/scheduler/commit_earlyout_reason.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"
@@ skipping 19 matching lines @@
     LayerTreeHostSingleThreadClient* client,
     scoped_refptr<base::SingleThreadTaskRunner> main_task_runner,
     scoped_ptr<BeginFrameSource> external_begin_frame_source)
     : Proxy(main_task_runner, NULL),
       layer_tree_host_(layer_tree_host),
       client_(client),
       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),
       inside_synchronous_composite_(false),
       output_surface_creation_requested_(false),
       external_begin_frame_source_(external_begin_frame_source.Pass()),
       weak_factory_(this) {
   TRACE_EVENT0("cc", "SingleThreadProxy::SingleThreadProxy");
   DCHECK(Proxy::IsMainThread());
   DCHECK(layer_tree_host);
 }
 
@@ skipping 25 matching lines @@
 
 void SingleThreadProxy::SetLayerTreeHostClientReady() {
   TRACE_EVENT0("cc", "SingleThreadProxy::SetLayerTreeHostClientReady");
   // Scheduling is controlled by the embedder in the single thread case, so
   // nothing to do.
   DCHECK(Proxy::IsMainThread());
   DebugScopedSetImplThread impl(this);
   if (layer_tree_host_->settings().single_thread_proxy_scheduler &&
       !scheduler_on_impl_thread_) {
     SchedulerSettings scheduler_settings(layer_tree_host_->settings());
+    // SingleThreadProxy should run in main thread low latency mode.
     scheduler_settings.main_thread_should_always_be_low_latency = true;
     scheduler_on_impl_thread_ =
         Scheduler::Create(this,
                           scheduler_settings,
                           layer_tree_host_->id(),
                           MainThreadTaskRunner(),
                           base::PowerMonitor::Get(),
                           external_begin_frame_source_.Pass());
     scheduler_on_impl_thread_->SetCanStart();
     scheduler_on_impl_thread_->SetVisible(layer_tree_host_impl_->visible());
@@ skipping 24 matching lines @@
   if (output_surface_creation_requested_)
     return;
   output_surface_creation_requested_ = true;
   layer_tree_host_->RequestNewOutputSurface();
 }
 
 void SingleThreadProxy::SetOutputSurface(
     scoped_ptr<OutputSurface> output_surface) {
   DCHECK(Proxy::IsMainThread());
   DCHECK(layer_tree_host_->output_surface_lost());
-  output_surface_creation_requested_ = false;
+  DCHECK(output_surface_creation_requested_);
   renderer_capabilities_for_main_thread_ = RendererCapabilities();
 
   bool success;
   {
     DebugScopedSetMainThreadBlocked main_thread_blocked(this);
     DebugScopedSetImplThread impl(this);
     layer_tree_host_->DeleteContentsTexturesOnImplThread(
         layer_tree_host_impl_->resource_provider());
     success = layer_tree_host_impl_->InitializeRenderer(output_surface.Pass());
   }
 
   if (success) {
     layer_tree_host_->DidInitializeOutputSurface();
     if (scheduler_on_impl_thread_)
       scheduler_on_impl_thread_->DidCreateAndInitializeOutputSurface();
     else if (!inside_synchronous_composite_)
       SetNeedsCommit();
+    output_surface_creation_requested_ = false;
   } else {
+    // DidFailToInitializeOutputSurface is treated as a RequestNewOutputSurface,
+    // and so output_surface_creation_requested remains true.
     layer_tree_host_->DidFailToInitializeOutputSurface();
   }
 }
 
 const RendererCapabilities& SingleThreadProxy::GetRendererCapabilities() const {
   DCHECK(Proxy::IsMainThread());
   DCHECK(!layer_tree_host_->output_surface_lost());
   return renderer_capabilities_for_main_thread_;
 }
 
@@ skipping 135 matching lines @@
     return;
   if (defer_commits_ == defer_commits)
     return;
 
   if (defer_commits)
     TRACE_EVENT_ASYNC_BEGIN0("cc", "SingleThreadProxy::SetDeferCommits", this);
   else
     TRACE_EVENT_ASYNC_END0("cc", "SingleThreadProxy::SetDeferCommits", this);
 
   defer_commits_ = defer_commits;
-  if (!defer_commits_ && commit_was_deferred_) {
-    commit_was_deferred_ = false;
-    BeginMainFrame();
-  }
+  scheduler_on_impl_thread_->SetDeferCommits(defer_commits);
 }
 
 bool SingleThreadProxy::CommitRequested() const {
   DCHECK(Proxy::IsMainThread());
   return commit_requested_;
 }
 
 bool SingleThreadProxy::BeginMainFrameRequested() const {
   DCHECK(Proxy::IsMainThread());
   // If there is no scheduler, then there can be no pending begin frame,
@@ skipping 101 matching lines @@
 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_->SetRequiresHighResToDraw();
 
+    // Synchronously call to CommitComplete. Resetting
+    // |commit_blocking_task_runner| would make sure all tasks posted during
+    // commit/activation before CommitComplete.
     CommitComplete();
   }
 
   timing_history_.DidActivateSyncTree();
 }
 
 void SingleThreadProxy::DidPrepareTiles() {
   DCHECK(layer_tree_host_impl_->settings().impl_side_painting);
   DCHECK(Proxy::IsImplThread());
   if (scheduler_on_impl_thread_)
@@ skipping 219 matching lines @@
   // ThreadProxy::SetNeedsCommit where SetNeedsCommit will not cause a
   // synchronous commit.
   MainThreadTaskRunner()->PostTask(
       FROM_HERE,
       base::Bind(&SingleThreadProxy::BeginMainFrame,
                  weak_factory_.GetWeakPtr()));
 }
 
 void SingleThreadProxy::BeginMainFrame() {
   if (defer_commits_) {
-    DCHECK(!commit_was_deferred_);
-    commit_was_deferred_ = true;
-    layer_tree_host_->DidDeferCommit();
+    TRACE_EVENT_INSTANT0("cc", "EarlyOut_DeferCommit",
+                         TRACE_EVENT_SCOPE_THREAD);
+    BeginMainFrameAbortedOnImplThread(
+        CommitEarlyOutReason::ABORTED_DEFERRED_COMMIT);
     return;
   }
 
   // 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(
@@ skipping 122 matching lines @@
 
 void SingleThreadProxy::DidBeginImplFrameDeadline() {
   layer_tree_host_impl_->ResetCurrentBeginFrameArgsForNextFrame();
 }
 
 void SingleThreadProxy::SendBeginFramesToChildren(const BeginFrameArgs& args) {
   layer_tree_host_->SendBeginFramesToChildren(args);
 }
 
 }  // namespace cc