cc: Remove retro frames from 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 2d0ee144d196422a57bc8fba33ccd3a9a6c08a07..5ff286765f64c04408558dc3b13514e127eded4e 100644
--- a/cc/scheduler/scheduler_state_machine.h
+++ b/cc/scheduler/scheduler_state_machine.h
@@ -63,7 +63,6 @@ class CC_EXPORT SchedulerStateMachine {
   // DRAW.
   enum BeginImplFrameState {
     BEGIN_IMPL_FRAME_STATE_IDLE,
-    BEGIN_IMPL_FRAME_STATE_BEGIN_FRAME_STARTING,
     BEGIN_IMPL_FRAME_STATE_INSIDE_BEGIN_FRAME,
     BEGIN_IMPL_FRAME_STATE_INSIDE_DEADLINE,
   };
@@ -153,7 +152,6 @@ class CC_EXPORT SchedulerStateMachine {
   // The scheduler will not draw more than once in a given BeginImplFrame
   // callback nor send more than one BeginMainFrame message.
   void OnBeginImplFrame();
-  void OnBeginImplFrameDeadlinePending();
   // Indicates that the scheduler has entered the draw phase. The scheduler
   // will not draw more than once in a single draw phase.
   // TODO(sunnyps): Rename OnBeginImplFrameDeadline to OnDraw or similar.