cc: Control defer_commits logic by Scheduler

cc/scheduler/scheduler_state_machine.cc

Index: cc/scheduler/scheduler_state_machine.cc
diff --git a/cc/scheduler/scheduler_state_machine.cc b/cc/scheduler/scheduler_state_machine.cc
index 5f56255926f47b667cf9f39aa28e85e3ab3dff05..154e5cd5bf0052b4f44475a295e80afe30a228d2 100644
--- a/cc/scheduler/scheduler_state_machine.cc
+++ b/cc/scheduler/scheduler_state_machine.cc
@@ -48,7 +48,8 @@ SchedulerStateMachine::SchedulerStateMachine(const SchedulerSettings& settings)
       skip_begin_main_frame_to_reduce_latency_(false),
       continuous_painting_(false),
       impl_latency_takes_priority_on_battery_(false),
-      children_need_begin_frames_(false) {
+      children_need_begin_frames_(false),
+      defer_commits_(false) {
 }
 
 const char* SchedulerStateMachine::OutputSurfaceStateToString(
@@ -236,6 +237,7 @@ void SchedulerStateMachine::AsValueInto(base::debug::TracedValue* state,
   state->SetBoolean("impl_latency_takes_priority_on_battery",
                     impl_latency_takes_priority_on_battery_);
   state->SetBoolean("children_need_begin_frames", children_need_begin_frames_);
+  state->SetBoolean("defer_commits", defer_commits_);
   state->EndDictionary();
 }
 
@@ -404,6 +406,10 @@ bool SchedulerStateMachine::CouldSendBeginMainFrame() const {
   if (!visible_)
     return false;
 
+  // We do not need new commits if it is deferred.
+  if (defer_commits_)
+    return false;
+
   return true;
 }
 
@@ -727,6 +733,10 @@ void SchedulerStateMachine::SetChildrenNeedBeginFrames(
   children_need_begin_frames_ = children_need_begin_frames;
 }
 
+void SchedulerStateMachine::SetDeferCommits(bool defer_commits) {
+  defer_commits_ = defer_commits;
+}
+
 // These are the cases where we definitely (or almost definitely) have a
 // new frame to animate and/or draw and can draw.
 bool SchedulerStateMachine::BeginFrameNeededToAnimateOrDraw() const {