We have a problem in the process on destroying WebContentsImpl because

chrome/browser/extensions/webstore_inline_installer.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_WEBSTORE_INLINE_INSTALLER_H_
 #define CHROME_BROWSER_EXTENSIONS_WEBSTORE_INLINE_INSTALLER_H_
 
 #include <string>
 
 #include "base/memory/ref_counted.h"
@@ skipping 40 matching lines @@
       CreateInstallPrompt() const OVERRIDE;
   virtual bool CheckInlineInstallPermitted(
       const base::DictionaryValue& webstore_data,
       std::string* error) const OVERRIDE;
   virtual bool CheckRequestorPermitted(
       const base::DictionaryValue& webstore_data,
       std::string* error) const OVERRIDE;
 
  private:
   // content::WebContentsObserver interface implementation.
-  virtual void WebContentsDestroyed(
-      content::WebContents* web_contents) OVERRIDE;
+  virtual void WebContentsDestroyed() OVERRIDE;
 
   // Checks whether the install is initiated by a page in a verified site
   // (which is at least a domain, but can also have a port or a path).
   static bool IsRequestorURLInVerifiedSite(const GURL& requestor_url,
                                            const std::string& verified_site);
 
   GURL requestor_url_;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(WebstoreInlineInstaller);
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_WEBSTORE_INLINE_INSTALLER_H_