We have a problem in the process on destroying WebContentsImpl because

chrome/browser/extensions/active_tab_permission_granter.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 CHROME_BROWSER_EXTENSIONS_ACTIVE_TAB_PERMISSION_GRANTER_H_
 #define CHROME_BROWSER_EXTENSIONS_ACTIVE_TAB_PERMISSION_GRANTER_H_
 
 #include <set>
 #include <string>
 
@@ skipping 27 matching lines @@
 
   // If |extension| has the activeTab or tabCapture permission, grants
   // tab-specific permissions to it until the next page navigation or refresh.
   void GrantIfRequested(const Extension* extension);
 
  private:
   // content::WebContentsObserver implementation.
   virtual void DidNavigateMainFrame(
       const content::LoadCommittedDetails& details,
       const content::FrameNavigateParams& params) OVERRIDE;
-  virtual void WebContentsDestroyed(content::WebContents* web_contents)
-      OVERRIDE;
+  virtual void WebContentsDestroyed() OVERRIDE;
 
   // extensions::ExtensionRegistryObserver implementation.
   virtual void OnExtensionUnloaded(content::BrowserContext* browser_context,
                                    const Extension* extension,
                                    UnloadedExtensionInfo::Reason reason)
       OVERRIDE;
 
   // Clears any tab-specific permissions for all extensions on |tab_id_| and
   // notifies renderers.
   void ClearActiveExtensionsAndNotify();
 
   // The tab ID for this tab.
   int tab_id_;
 
   // Extensions with the activeTab permission that have been granted
   // tab-specific permissions until the next navigation/refresh.
   ExtensionSet granted_extensions_;
 
   // Listen to extension unloaded notifications.
   ScopedObserver<ExtensionRegistry, ExtensionRegistryObserver>
       extension_registry_observer_;
 
   DISALLOW_COPY_AND_ASSIGN(ActiveTabPermissionGranter);
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_ACTIVE_TAB_PERMISSION_GRANTER_H_