Add latency measurement system

content/browser/renderer_host/render_widget_host_impl.h

Index: content/browser/renderer_host/render_widget_host_impl.h
diff --git a/content/browser/renderer_host/render_widget_host_impl.h b/content/browser/renderer_host/render_widget_host_impl.h
index 7549ac2d3fa9199a5ee27dc8c476a1a0c73cefc9..856c0d70d0ce6182bc528e3c7826f3f74b4803d8 100644
--- a/content/browser/renderer_host/render_widget_host_impl.h
+++ b/content/browser/renderer_host/render_widget_host_impl.h
@@ -41,6 +41,7 @@ class TimeTicks;
 
 namespace cc {
 class CompositorFrame;
+struct LatencyInfo;
 }
 
 namespace ui {
@@ -403,6 +404,11 @@ class CONTENT_EXPORT RenderWidgetHostImpl : virtual public RenderWidgetHost,
   void ParentChanged(gfx::NativeViewId new_parent);
 #endif
 
+  static void NotifyFrameDisplayed(
+      int route_id,
+      int gpu_host_id,
+      const cc::LatencyInfo& latency_info);
+
   // Signals that the compositing surface was updated, e.g. after a lost context
   // event.
   void CompositingSurfaceUpdated();
@@ -672,6 +678,13 @@ class CONTENT_EXPORT RenderWidgetHostImpl : virtual public RenderWidgetHost,
   // initiated by OnBeginSmoothScroll.
   void TickActiveSmoothScrollGesture();
 
+  // Called when an input event has arrived, to increment the input number id.
+  void IncrementInputNumber();
+
+  // Called before a message is sent that should cause the renderer to produce
+  // a new frame.
+  void SendStartFrame();
+
   // Our delegate, which wants to know mainly about keyboard events.
   // It will remain non-NULL until DetachDelegate() is called.
   RenderWidgetHostDelegate* delegate_;
@@ -861,6 +874,9 @@ class CONTENT_EXPORT RenderWidgetHostImpl : virtual public RenderWidgetHost,
   scoped_ptr<GestureEventFilter> gesture_event_filter_;
   scoped_ptr<OverscrollController> overscroll_controller_;
 
+  bool incremented_input_number_;
+  int64 current_input_number_;
+
 #if defined(OS_WIN)
   std::list<HWND> dummy_windows_for_activation_;
 #endif