Support frame tree propagation between renderers in the same browsing instance.

content/browser/renderer_host/render_view_host_delegate.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CONTENT_BROWSER_RENDERER_HOST_RENDER_VIEW_HOST_DELEGATE_H_
 #define CONTENT_BROWSER_RENDERER_HOST_RENDER_VIEW_HOST_DELEGATE_H_
 
 #include <string>
 
 #include "base/basictypes.h"
@@ skipping 197 matching lines @@
   virtual void DidStopLoading(RenderViewHost* render_view_host) {}
 
   // The pending page load was canceled.
   virtual void DidCancelLoading() {}
 
   // The RenderView made progress loading a page's top frame.
   // |progress| is a value between 0 (nothing loaded) to 1.0 (top frame
   // entirely loaded).
   virtual void DidChangeLoadProgress(double progress) {}
 
+  // The RenderView has changed its frame hierarchy, so we need to update all
+  // other renderers interested in this event.
+  virtual void DidUpdateFrameTree(RenderViewHost* rvh) {}
+
   // The RenderView's main frame document element is ready. This happens when
   // the document has finished parsing.
   virtual void DocumentAvailableInMainFrame(RenderViewHost* render_view_host) {}
 
   // The onload handler in the RenderView's main frame has completed.
   virtual void DocumentOnLoadCompletedInMainFrame(
       RenderViewHost* render_view_host,
       int32 page_id) {}
 
   // The page wants to open a URL with the specified disposition.
@@ skipping 177 matching lines @@
       const MediaStreamRequest* request,
       const MediaResponseCallback& callback) {}
 
  protected:
   virtual ~RenderViewHostDelegate() {}
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_RENDER_VIEW_HOST_DELEGATE_H_