We have a problem in the process on destroying WebContentsImpl because

content/browser/frame_host/interstitial_page_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_BROWSER_FRAME_HOST_INTERSTITIAL_PAGE_IMPL_H_
 #define CONTENT_BROWSER_FRAME_HOST_INTERSTITIAL_PAGE_IMPL_H_
 
 #include "base/compiler_specific.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
@@ skipping 50 matching lines @@
   virtual void Show() OVERRIDE;
   virtual void Hide() OVERRIDE;
   virtual void DontProceed() OVERRIDE;
   virtual void Proceed() OVERRIDE;
   virtual RenderViewHost* GetRenderViewHostForTesting() const OVERRIDE;
   virtual InterstitialPageDelegate* GetDelegateForTesting() OVERRIDE;
   virtual void DontCreateViewForTesting() OVERRIDE;
   virtual void SetSize(const gfx::Size& size) OVERRIDE;
   virtual void Focus() OVERRIDE;
 
-  // This is called by a hosting WebContents to notify this interstitial page
-  // that it is going away.
-  void WebContentsWillBeDestroyed();
-
   // Allows the user to navigate away by disabling the interstitial, canceling
   // the pending request, and unblocking the hidden renderer.  The interstitial
   // will stay visible until the navigation completes.
   void CancelForNavigation();
 
   // Focus the first (last if reverse is true) element in the interstitial page.
   // Called when tab traversing.
   void FocusThroughTabTraversal(bool reverse);
 
   RenderWidgetHostView* GetView();
@@ skipping 17 matching lines @@
       const FrameHostMsg_DidCommitProvisionalLoad_Params& params);
 
  protected:
   // NotificationObserver method:
   virtual void Observe(int type,
                        const NotificationSource& source,
                        const NotificationDetails& details) OVERRIDE;
 
   // WebContentsObserver implementation:
   virtual bool OnMessageReceived(const IPC::Message& message) OVERRIDE;
-  virtual void WebContentsDestroyed(WebContents* web_contents) OVERRIDE;
+  virtual void WebContentsDestroyed() OVERRIDE;
   virtual void NavigationEntryCommitted(
       const LoadCommittedDetails& load_details) OVERRIDE;
 
   // RenderFrameHostDelegate implementation:
   virtual bool OnMessageReceived(RenderFrameHost* render_frame_host,
                                  const IPC::Message& message) OVERRIDE;
   virtual void RenderFrameCreated(RenderFrameHost* render_frame_host) OVERRIDE;
 
   // RenderViewHostDelegate implementation:
   virtual RenderViewHostDelegateView* GetDelegateView() OVERRIDE;
@@ skipping 163 matching lines @@
   base::WeakPtrFactory<InterstitialPageImpl> weak_ptr_factory_;
 
   scoped_refptr<SessionStorageNamespace> session_storage_namespace_;
 
   DISALLOW_COPY_AND_ASSIGN(InterstitialPageImpl);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_FRAME_HOST_INTERSTITIAL_PAGE_IMPL_H_