cc: Make SingleThreadProxy ignore commit requests inside Layout().

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/profiler/scoped_tracker.h"
 #include "base/trace_event/trace_event.h"
 #include "cc/debug/benchmark_instrumentation.h"
@@ skipping 32 matching lines @@
     : 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_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);
+
+  if (layer_tree_host->settings().single_thread_proxy_scheduler &&
+      !scheduler_on_impl_thread_) {
+    SchedulerSettings scheduler_settings(
+        layer_tree_host->settings().ToSchedulerSettings());
+    // 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(), external_begin_frame_source.Pass());
+  }
 }
 
 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 20 matching lines @@
   // active tree.
   return true;
 }
 
 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().ToSchedulerSettings());
-    // 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(),
-                          external_begin_frame_source_.Pass());
+  if (scheduler_on_impl_thread_) {
     scheduler_on_impl_thread_->SetCanStart();
     scheduler_on_impl_thread_->SetVisible(layer_tree_host_impl_->visible());
   }
 }
 
 void SingleThreadProxy::SetVisible(bool visible) {
   TRACE_EVENT1("cc", "SingleThreadProxy::SetVisible", "visible", visible);
   DebugScopedSetImplThread impl(this);
   layer_tree_host_impl_->SetVisible(visible);
   if (scheduler_on_impl_thread_)
@@ skipping 87 matching lines @@
 }
 
 void SingleThreadProxy::DoCommit() {
   TRACE_EVENT0("cc", "SingleThreadProxy::DoCommit");
   DCHECK(Proxy::IsMainThread());
 
   // TODO(robliao): Remove ScopedTracker below once https://crbug.com/461509 is
   // fixed.
   tracked_objects::ScopedTracker tracking_profile1(
       FROM_HERE_WITH_EXPLICIT_FUNCTION("461509 SingleThreadProxy::DoCommit1"));
-  commit_requested_ = false;
   layer_tree_host_->WillCommit();
   devtools_instrumentation::ScopedCommitTrace commit_task(
       layer_tree_host_->id());
 
   // Commit immediately.
   {
     // TODO(robliao): Remove ScopedTracker below once https://crbug.com/461509
     // is fixed.
     tracked_objects::ScopedTracker tracking_profile2(
         FROM_HERE_WITH_EXPLICIT_FUNCTION(
@@ skipping 99 matching lines @@
   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());
+  client_->ScheduleComposite();
+  if (commit_requested_)
+    return;
   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();
@@ skipping 410 matching lines @@
 
 void SingleThreadProxy::DidCommitAndDrawFrame() {
   if (next_frame_is_newly_committed_frame_) {
     DebugScopedSetMainThread main(this);
     next_frame_is_newly_committed_frame_ = false;
     layer_tree_host_->DidCommitAndDrawFrame();
   }
 }
 
 bool SingleThreadProxy::MainFrameWillHappenForTesting() {
-  return false;
+  if (layer_tree_host_->output_surface_lost())
+    return false;
+  if (!scheduler_on_impl_thread_)
+    return false;
+  return scheduler_on_impl_thread_->MainFrameForTestingWillHappen();
 }
 
 void SingleThreadProxy::SetChildrenNeedBeginFrames(
     bool children_need_begin_frames) {
   scheduler_on_impl_thread_->SetChildrenNeedBeginFrames(
       children_need_begin_frames);
 }
 
 void SingleThreadProxy::SetAuthoritativeVSyncInterval(
     const base::TimeDelta& interval) {
@@ skipping 17 matching lines @@
       FROM_HERE,
       base::Bind(&SingleThreadProxy::BeginMainFrame,
                  weak_factory_.GetWeakPtr()));
 }
 
 void SingleThreadProxy::SendBeginMainFrameNotExpectedSoon() {
   layer_tree_host_->BeginMainFrameNotExpectedSoon();
 }
 
 void SingleThreadProxy::BeginMainFrame() {
+  commit_requested_ = false;
+
   if (defer_commits_) {
     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(
         CommitEarlyOutReason::ABORTED_NOT_VISIBLE);
     return;
   }
 
   if (layer_tree_host_->output_surface_lost()) {
     TRACE_EVENT_INSTANT0(
         "cc", "EarlyOut_OutputSurfaceLost", TRACE_EVENT_SCOPE_THREAD);
     BeginMainFrameAbortedOnImplThread(
         CommitEarlyOutReason::ABORTED_OUTPUT_SURFACE_LOST);
     return;
   }
 
+  // Prevent new commits from being requested inside DoBeginMainFrame.
+  commit_requested_ = true;
+
   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);
 
+  // New commits requested inside UpdateLayers should be respected.
+  commit_requested_ = false;
+
   layer_tree_host_->UpdateLayers(queue_for_commit_.get());
 
   timing_history_.DidBeginMainFrame();
 
   // TODO(enne): SingleThreadProxy does not support cancelling commits yet,
   // search for CommitEarlyOutReason::FINISHED_NO_UPDATES inside
   // thread_proxy.cc
   if (scheduler_on_impl_thread_) {
     scheduler_on_impl_thread_->NotifyBeginMainFrameStarted();
     scheduler_on_impl_thread_->NotifyReadyToCommit();
@@ skipping 80 matching lines @@
 
 void SingleThreadProxy::DidBeginImplFrameDeadline() {
   layer_tree_host_impl_->ResetCurrentBeginFrameArgsForNextFrame();
 }
 
 void SingleThreadProxy::SendBeginFramesToChildren(const BeginFrameArgs& args) {
   layer_tree_host_->SendBeginFramesToChildren(args);
 }
 
 }  // namespace cc