Pass RenderFrameHost to WebContentObservers' message handlers

content/public/browser/web_contents_observer.h

Index: content/public/browser/web_contents_observer.h
diff --git a/content/public/browser/web_contents_observer.h b/content/public/browser/web_contents_observer.h
index 9fae539faf6e3a97c3198e6d95a3e703202a7982..25279c2b66f54d6a38740b14fb9de8da0cf1c064 100644
--- a/content/public/browser/web_contents_observer.h
+++ b/content/public/browser/web_contents_observer.h
@@ -332,6 +332,12 @@ class CONTENT_EXPORT WebContentsObserver : public IPC::Listener,
   virtual void AccessibilityEventReceived(
       const std::vector<AXEventNotificationDetails>& details) {}
 
+  // Invoked if an IPC message is coming from a specific RenderFrameHost.
+  // The default implementation simply delegates to the RFH-less version of
+  // OnMessageReceived.
+  virtual bool OnMessageReceived(RenderFrameHost* render_frame_host,
+                                 const IPC::Message& message);
+
   // IPC::Listener implementation.
   virtual bool OnMessageReceived(const IPC::Message& message) OVERRIDE;