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 7c335f404fc007b239362c45d8cdc0febaed79ab..fdd26006438b21b5bcb503f9d14984ced619b83d 100644
--- a/content/browser/renderer_host/render_widget_host_impl.h
+++ b/content/browser/renderer_host/render_widget_host_impl.h
@@ -47,6 +47,7 @@ namespace WebKit {
 class WebInputEvent;
 class WebMouseEvent;
 struct WebCompositionUnderline;
+struct WebLatencyInfoImpl;
 struct WebScreenInfo;
 }
 
@@ -412,6 +413,11 @@ 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 WebKit::WebLatencyInfoImpl& latency_info);
+
   // Signals that the compositing surface was updated, e.g. after a lost context
   // event.
   void CompositingSurfaceUpdated();
@@ -684,6 +690,13 @@ class CONTENT_EXPORT RenderWidgetHostImpl : virtual public RenderWidgetHost,
   // initiated by OnMsgBeginSmoothScroll.
   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_;
@@ -873,6 +886,9 @@ 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