cc: Remove background ticking from LTHI.

cc/scheduler/scheduler.h

Index: cc/scheduler/scheduler.h
diff --git a/cc/scheduler/scheduler.h b/cc/scheduler/scheduler.h
index 3a4af5a1930227cde95a5f2347609e0b44df481d..b4c20fe3062a6cc579668d4a8a99dfed53777a4c 100644
--- a/cc/scheduler/scheduler.h
+++ b/cc/scheduler/scheduler.h
@@ -62,8 +62,6 @@ class CC_EXPORT SchedulerFrameSourcesConstructor {
  public:
   virtual ~SchedulerFrameSourcesConstructor() {}
   virtual BeginFrameSource* ConstructPrimaryFrameSource(Scheduler* scheduler);
-  virtual BeginFrameSource* ConstructBackgroundFrameSource(
-      Scheduler* scheduler);
   virtual BeginFrameSource* ConstructUnthrottledFrameSource(
       Scheduler* scheduler);
 
@@ -182,12 +180,10 @@ 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_;