Invalidate the previous frame when the window object is cleared.

content/renderer/render_frame_impl.h

 // Copyright 2013 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_RENDERER_RENDER_FRAME_IMPL_H_
 #define CONTENT_RENDERER_RENDER_FRAME_IMPL_H_
 
 #include <vector>
 
 #include "base/basictypes.h"
@@ skipping 342 matching lines @@
                                        bool is_transition_navigation);
   virtual void didReceiveServerRedirectForProvisionalLoad(
       blink::WebLocalFrame* frame);
   virtual void didFailProvisionalLoad(
       blink::WebLocalFrame* frame,
       const blink::WebURLError& error);
   virtual void didCommitProvisionalLoad(
       blink::WebLocalFrame* frame,
       const blink::WebHistoryItem& item,
       blink::WebHistoryCommitType commit_type);
+  virtual void didCreateNewDocument(blink::WebLocalFrame* frame);
   virtual void didClearWindowObject(blink::WebLocalFrame* frame);
   virtual void didCreateDocumentElement(blink::WebLocalFrame* frame);
   virtual void didReceiveTitle(blink::WebLocalFrame* frame,
                                const blink::WebString& title,
                                blink::WebTextDirection direction);
   virtual void didChangeIcon(blink::WebLocalFrame* frame,
                              blink::WebIconURL::Type icon_type);
   virtual void didFinishDocumentLoad(blink::WebLocalFrame* frame);
   virtual void didHandleOnloadEvents(blink::WebLocalFrame* frame);
   virtual void didFailLoad(blink::WebLocalFrame* frame,
@@ skipping 420 matching lines @@
 #endif
 
   base::WeakPtrFactory<RenderFrameImpl> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(RenderFrameImpl);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_RENDER_FRAME_IMPL_H_