cc: Heuristic for Renderer latency recovery

cc/scheduler/scheduler.h

Index: cc/scheduler/scheduler.h
diff --git a/cc/scheduler/scheduler.h b/cc/scheduler/scheduler.h
index 967d31b7f5912a192ae32daf6d38f1d1a436db22..6d5cd9ce134f92f26e01b80a98491748e5b691b1 100644
--- a/cc/scheduler/scheduler.h
+++ b/cc/scheduler/scheduler.h
@@ -120,9 +120,6 @@ class CC_EXPORT Scheduler : public BeginFrameObserverBase {
   bool PrepareTilesPending() const {
     return state_machine_.PrepareTilesPending();
   }
-  bool MainThreadIsInHighLatencyMode() const {
-    return state_machine_.MainThreadIsInHighLatencyMode();
-  }
   bool BeginImplFrameDeadlinePending() const {
     return !begin_impl_frame_deadline_task_.IsCancelled();
   }
@@ -192,7 +189,7 @@ class CC_EXPORT Scheduler : public BeginFrameObserverBase {
   bool inside_process_scheduled_actions_;
   SchedulerStateMachine::Action inside_action_;
 
- private:
+ protected:
   void ScheduleBeginImplFrameDeadline();
   void ScheduleBeginImplFrameDeadlineIfNeeded();
   void SetupNextBeginFrameIfNeeded();
@@ -201,11 +198,14 @@ class CC_EXPORT Scheduler : public BeginFrameObserverBase {
   void DrawAndSwapForced();
   void ProcessScheduledActions();
   void UpdateCompositorTimingHistoryRecordingEnabled();
-  bool CanCommitAndActivateBeforeDeadline() const;
+  bool ShouldRecoverMainLatency(const BeginFrameArgs& args) const;
+  bool ShouldRecoverImplLatency(const BeginFrameArgs& args) const;
+  bool CanCommitAndActivateBeforeDeadline(const BeginFrameArgs& args) const;
   void AdvanceCommitStateIfPossible();
   bool IsBeginMainFrameSentOrStarted() const;
   void BeginRetroFrame();
-  void BeginImplFrameWithDeadline(const BeginFrameArgs& args);
+  // virtual for testing.
+  virtual void BeginImplFrameWithDeadline(const BeginFrameArgs& args);
   void BeginImplFrameSynchronous(const BeginFrameArgs& args);
   void BeginImplFrame(const BeginFrameArgs& args);
   void FinishImplFrame();
@@ -230,6 +230,7 @@ class CC_EXPORT Scheduler : public BeginFrameObserverBase {
 
   base::WeakPtrFactory<Scheduler> weak_factory_;
 
+ private:
   DISALLOW_COPY_AND_ASSIGN(Scheduler);
 };