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..a0c5eb8cd038b0f98700b231601d82e2565a6888 100644
--- a/content/public/browser/web_contents_observer.h
+++ b/content/public/browser/web_contents_observer.h
@@ -332,6 +332,14 @@ 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.  This
+  // handler is called for messages sent from renderers via RenderFrame::Send or
+  // RenderFrameObserver::Send. Such messages are not passed to the generic
+  // OnMessageReceived handler (derived from IPC::Listener) to avoid
+  // possibilities for cross-site interaction.

[jam, 2014/05/02 19:41:22]

nit: remove "or RenderFrameObserver::Send" since there are various wayts to get
to RF::Send and we don't want to enumerate them all here.

"cross-site interaction" is going to be a bit cryptic for most devs. i would
just remove this last sentance.

[mnaganov (inactive), 2014/05/06 09:06:46]

Done.

+  virtual bool OnMessageReceived(const IPC::Message& message,
+                                 RenderFrameHost* render_frame_host);
+
   // IPC::Listener implementation.
   virtual bool OnMessageReceived(const IPC::Message& message) OVERRIDE;