Added ability to dynamically toggle frame throttling in the scheduler.

cc/scheduler/scheduler.h

Index: cc/scheduler/scheduler.h
diff --git a/cc/scheduler/scheduler.h b/cc/scheduler/scheduler.h
index dea7c3e541004fd0bce31f182b501ca0e16be845..addd5aa5717c87df084b1c296d89b0c4840179d5 100644
--- a/cc/scheduler/scheduler.h
+++ b/cc/scheduler/scheduler.h
@@ -65,6 +65,8 @@ class CC_EXPORT SchedulerFrameSourcesConstructor {
   virtual BeginFrameSource* ConstructPrimaryFrameSource(Scheduler* scheduler);
   virtual BeginFrameSource* ConstructBackgroundFrameSource(
       Scheduler* scheduler);
+  virtual BeginFrameSource* ConstructUnthrottledFrameSource(
+      Scheduler* scheduler);
 
  protected:
   SchedulerFrameSourcesConstructor() {}
@@ -112,6 +114,7 @@ class CC_EXPORT Scheduler : public BeginFrameObserverMixIn,
   void SetCanDraw(bool can_draw);
   void NotifyReadyToActivate();
   void NotifyReadyToDraw();
+  void SetThrottleFrameProduction(bool throttle);
 
   void SetNeedsCommit();
 
@@ -184,12 +187,15 @@ class CC_EXPORT Scheduler : public BeginFrameObserverMixIn,
   scoped_ptr<BeginFrameSourceMultiplexer> frame_source_;
   BeginFrameSource* primary_frame_source_;
   BeginFrameSource* background_frame_source_;
+  BeginFrameSource* unthrottled_frame_source_;
 
   // Storage when frame sources are internal
   scoped_ptr<BeginFrameSource> primary_frame_source_internal_;
   scoped_ptr<SyntheticBeginFrameSource> background_frame_source_internal_;
+  scoped_ptr<BeginFrameSource> unthrottled_frame_source_internal_;
 
   VSyncParameterObserver* vsync_observer_;
+  bool throttle_frame_production_;
 
   const SchedulerSettings settings_;
   SchedulerClient* client_;
@@ -238,6 +244,7 @@ class CC_EXPORT Scheduler : public BeginFrameObserverMixIn,
   void PollToAdvanceCommitState();
   void SetupPowerMonitoring();
   void TeardownPowerMonitoring();
+  void UpdateActiveFrameSource();
 
   base::TimeDelta EstimatedParentDrawTime() {
     return estimated_parent_draw_time_;