cc: Control defer_commits logic by Scheduler

cc/scheduler/scheduler_state_machine.h

Index: cc/scheduler/scheduler_state_machine.h
diff --git a/cc/scheduler/scheduler_state_machine.h b/cc/scheduler/scheduler_state_machine.h
index a2a8b59e6c64b0f2ccfdfa9e760bc5920ce12bd7..4c5ec9e55915b407fb43bfaffab5e7c270efaba8 100644
--- a/cc/scheduler/scheduler_state_machine.h
+++ b/cc/scheduler/scheduler_state_machine.h
@@ -230,6 +230,8 @@ class CC_EXPORT SchedulerStateMachine {
     continuous_painting_ = continuous_painting;
   }
 
+  void SetDeferCommits(bool defer_commits);
+
  protected:
   bool BeginFrameNeededToAnimateOrDraw() const;
   bool ProactiveBeginFrameWanted() const;
@@ -300,6 +302,7 @@ class CC_EXPORT SchedulerStateMachine {
   bool skip_next_begin_main_frame_to_reduce_latency_;
   bool skip_begin_main_frame_to_reduce_latency_;
   bool continuous_painting_;
+  bool defer_commits_;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(SchedulerStateMachine);