We have a problem in the process on destroying WebContentsImpl because

chrome/browser/ui/website_settings/permission_bubble_manager.h

 // Copyright 2014 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 CHROME_BROWSER_UI_WEBSITE_SETTINGS_PERMISSION_BUBBLE_MANAGER_H_
 #define CHROME_BROWSER_UI_WEBSITE_SETTINGS_PERMISSION_BUBBLE_MANAGER_H_
 
 #include <vector>
 
 #include "base/memory/weak_ptr.h"
@@ skipping 56 matching lines @@
   // WebContentsObserver:
 
   // TODO(leng): Finalize policy for permission requests with iFrames.
   // DocumentLoadedInFrame() might be needed as well.
   virtual void DocumentOnLoadCompletedInMainFrame() OVERRIDE;
 
   // If a page on which permissions requests are pending is navigated,
   // they will be finalized as if canceled by the user.
   virtual void NavigationEntryCommitted(
       const content::LoadCommittedDetails& details) OVERRIDE;
-  virtual void WebContentsDestroyed(
-      content::WebContents* web_contents) OVERRIDE;
+  virtual void WebContentsDestroyed() OVERRIDE;
 
   // PermissionBubbleView::Delegate:
   virtual void ToggleAccept(int request_index, bool new_value) OVERRIDE;
   virtual void SetCustomizationMode() OVERRIDE;
   virtual void Accept() OVERRIDE;
   virtual void Deny() OVERRIDE;
   virtual void Closing() OVERRIDE;
 
   void ShowBubble();
 
@@ skipping 19 matching lines @@
   GURL request_url_;
   bool request_url_has_loaded_;
 
   std::vector<bool> accept_states_;
   bool customization_mode_;
 
   base::WeakPtrFactory<PermissionBubbleManager> weak_factory_;
 };
 
 #endif  // CHROME_BROWSER_UI_WEBSITE_SETTINGS_PERMISSION_BUBBLE_MANAGER_H_