Setting Accurate ScrollResult from Blink for Elastic Scroll.

content/renderer/render_widget.h

Index: content/renderer/render_widget.h
diff --git a/content/renderer/render_widget.h b/content/renderer/render_widget.h
index 92a0f387f119804f52f04ef666589fb1036323d1..f62a383d674f52790a09defbc88e0a4915a40795 100644
--- a/content/renderer/render_widget.h
+++ b/content/renderer/render_widget.h
@@ -573,6 +573,7 @@ class CONTENT_EXPORT RenderWidget
   // Called by OnHandleInputEvent() to forward a mouse wheel event to the
   // compositor thread, to effect the elastic overscroll effect.
   void ObserveWheelEventAndResult(const blink::WebMouseWheelEvent& wheel_event,
+                                  const gfx::Vector2dF& wheel_unused_delta,
                                   bool event_processed);
 
   // Check whether the WebWidget has any touch event handlers registered