Revert of Revert "cc: Make scheduler run incoming frame after previous deadline."

cc/scheduler/scheduler.h

Index: cc/scheduler/scheduler.h
diff --git a/cc/scheduler/scheduler.h b/cc/scheduler/scheduler.h
index d33084c862ba99cbf2156aefee67acbe0b01c9a1..ed609b313666106bf1b72a8c6ca6bb8ea48376e8 100644
--- a/cc/scheduler/scheduler.h
+++ b/cc/scheduler/scheduler.h
@@ -181,8 +181,8 @@
 
   BeginFrameTracker begin_impl_frame_tracker_;
   BeginFrameArgs begin_main_frame_args_;
-
-  base::Closure begin_impl_frame_deadline_closure_;
+  BeginFrameArgs missed_begin_frame_args_;
+
   base::CancelableClosure begin_impl_frame_deadline_task_;
   base::CancelableClosure missed_begin_frame_task_;
 
@@ -198,6 +198,8 @@
   void ScheduleBeginImplFrameDeadlineIfNeeded();
   void BeginImplFrameNotExpectedSoon();
   void SetupNextBeginFrameIfNeeded();
+  void StartObservingBeginFrameSource();
+  void StopObservingBeginFrameSource();
   void DrawIfPossible();
   void DrawForced();
   void ProcessScheduledActions();
@@ -212,6 +214,7 @@
       base::TimeTicks now) const;
   void AdvanceCommitStateIfPossible();
   bool IsBeginMainFrameSentOrStarted() const;
+  void BeginImplFrameMissed(const BeginFrameArgs& args);
   void BeginImplFrameWithDeadline(const BeginFrameArgs& args);
   void BeginImplFrameSynchronous(const BeginFrameArgs& args);
   void BeginImplFrame(const BeginFrameArgs& args, base::TimeTicks now);