Add ZoomLevelChanged and DidChangeScrollOffset to RenderViewObserver

content/public/renderer/render_view_observer.h

Index: content/public/renderer/render_view_observer.h
diff --git a/content/public/renderer/render_view_observer.h b/content/public/renderer/render_view_observer.h
index 471ce149ba4b3d744fc0aab3b887dacf9fe2d238..f331fea66085903dc17c8ca8a56faaecfc42c579 100644
--- a/content/public/renderer/render_view_observer.h
+++ b/content/public/renderer/render_view_observer.h
@@ -17,6 +17,7 @@ class WebFrame;
 class WebFormElement;
 class WebMediaPlayerClient;
 class WebMouseEvent;
+class WebMouseWheelEvent;
 class WebNode;
 class WebTouchEvent;
 class WebURL;
@@ -72,6 +73,7 @@ class CONTENT_EXPORT RenderViewObserver : public IPC::Channel::Listener,
   // These match the RenderView methods.
   virtual void DidHandleMouseEvent(const WebKit::WebMouseEvent& event) {}
   virtual void DidHandleTouchEvent(const WebKit::WebTouchEvent& event) {}
+  virtual void DidHandleWheelEvent(const WebKit::WebMouseWheelEvent& event) {}
 
   // These match incoming IPCs.
   virtual void ContextMenuAction(unsigned id) {}