Add latency measurement system

ui/compositor/compositor.h

Index: ui/compositor/compositor.h
diff --git a/ui/compositor/compositor.h b/ui/compositor/compositor.h
index aa773b25e7c330e3ad10c1908666fe60ed8e61e5..ef2f494e79a9628666d17d1b4e23d50eb1fbe7eb 100644
--- a/ui/compositor/compositor.h
+++ b/ui/compositor/compositor.h
@@ -215,6 +215,8 @@ class COMPOSITOR_EXPORT Compositor
   // the whole frame needs to be drawn.
   void ScheduleFullDraw();
 
+  int64 SetInputNumber(int64 input_number);
+
   // Reads the region |bounds_in_pixel| of the contents of the last rendered
   // frame into the given bitmap.
   // Returns false if the pixels could not be read.
@@ -268,7 +270,8 @@ class COMPOSITOR_EXPORT Compositor
   virtual void didCompleteSwapBuffers() OVERRIDE;
   virtual void scheduleComposite() OVERRIDE;
   virtual scoped_ptr<cc::FontAtlas> createFontAtlas() OVERRIDE;
-
+  virtual void onReceivedLatencyInfo(
+    const cc::LatencyInfo& latencyInfo) OVERRIDE;
 
   int last_started_frame() { return last_started_frame_; }
   int last_ended_frame() { return last_ended_frame_; }
@@ -310,6 +313,8 @@ class COMPOSITOR_EXPORT Compositor
   int last_started_frame_;
   int last_ended_frame_;
 
+  int64 frame_number_;
+
   bool disable_schedule_composite_;
 
   CompositorLock* compositor_lock_;