cc: Track BeginMainFrame more precisely in CompositorTimingHistory.

cc/scheduler/compositor_timing_history.h

Index: cc/scheduler/compositor_timing_history.h
diff --git a/cc/scheduler/compositor_timing_history.h b/cc/scheduler/compositor_timing_history.h
index e580c5e3d5bd09ba5172cb8f02f38f9e062610cf..a86cddd8282e9d453e3a9e073978841e8da50e25 100644
--- a/cc/scheduler/compositor_timing_history.h
+++ b/cc/scheduler/compositor_timing_history.h
@@ -34,7 +34,15 @@ class CC_EXPORT CompositorTimingHistory {
 
   void AsValueInto(base::trace_event::TracedValue* state) const;
 
+  // Deprecated.
   virtual base::TimeDelta BeginMainFrameToCommitDurationEstimate() const;
+
+  // The main thread responsiveness depends heavily on whether or not the
+  // on_critical_path flag is set, so we record response times separately.
+  virtual base::TimeDelta BeginMainFrameQueueDurationCriticalEstimate() const;
+  virtual base::TimeDelta BeginMainFrameQueueDurationNotCriticalEstimate()
+      const;
+  virtual base::TimeDelta BeginMainFrameStartToCommitDurationEstimate() const;
   virtual base::TimeDelta CommitToReadyToActivateDurationEstimate() const;
   virtual base::TimeDelta PrepareTilesDurationEstimate() const;
   virtual base::TimeDelta ActivateDurationEstimate() const;
@@ -42,7 +50,8 @@ class CC_EXPORT CompositorTimingHistory {
 
   void SetRecordingEnabled(bool enabled);
 
-  void WillBeginMainFrame();
+  void WillBeginMainFrame(bool on_critical_path);
+  void BeginMainFrameStarted(base::TimeTicks main_thread_start_time);
   void BeginMainFrameAborted();
   void DidCommit();
   void WillPrepareTiles();
@@ -59,13 +68,18 @@ class CC_EXPORT CompositorTimingHistory {
 
   bool enabled_;
 
-  RollingTimeDeltaHistory begin_main_frame_to_commit_duration_history_;
+  RollingTimeDeltaHistory begin_main_frame_sent_to_commit_duration_history_;
+  RollingTimeDeltaHistory begin_main_frame_queue_duration_critical_history_;
+  RollingTimeDeltaHistory begin_main_frame_queue_duration_not_critical_history_;
+  RollingTimeDeltaHistory begin_main_frame_start_to_commit_duration_history_;
   RollingTimeDeltaHistory commit_to_ready_to_activate_duration_history_;
   RollingTimeDeltaHistory prepare_tiles_duration_history_;
   RollingTimeDeltaHistory activate_duration_history_;
   RollingTimeDeltaHistory draw_duration_history_;
 
+  bool begin_main_frame_on_critical_path_;
   base::TimeTicks begin_main_frame_sent_time_;
+  base::TimeTicks begin_main_frame_start_time_;
   base::TimeTicks commit_time_;
   base::TimeTicks start_prepare_tiles_time_;
   base::TimeTicks start_activate_time_;