We have a problem in the process on destroying WebContentsImpl because

chrome/browser/safe_browsing/client_side_detection_host.h

 // Copyright (c) 2011 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_SAFE_BROWSING_CLIENT_SIDE_DETECTION_HOST_H_
 #define CHROME_BROWSER_SAFE_BROWSING_CLIENT_SIDE_DETECTION_HOST_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 49 matching lines @@
   virtual scoped_refptr<SafeBrowsingDatabaseManager> database_manager();
 
   // Returns whether the current page contains a malware or phishing safe
   // browsing match.
   bool DidPageReceiveSafeBrowsingMatch() const;
 
  protected:
   explicit ClientSideDetectionHost(content::WebContents* tab);
 
   // From content::WebContentsObserver.
-  virtual void WebContentsDestroyed(content::WebContents* tab) OVERRIDE;
+  virtual void WebContentsDestroyed() OVERRIDE;
 
   // Used for testing.
   void set_safe_browsing_managers(
       SafeBrowsingUIManager* ui_manager,
       SafeBrowsingDatabaseManager* database_manager);
 
  private:
   friend class ClientSideDetectionHostTest;
   class ShouldClassifyUrlRequest;
   friend class ShouldClassifyUrlRequest;
@@ skipping 96 matching lines @@
   // as well as the UnsafeResource.
   int unsafe_unique_page_id_;
   scoped_ptr<SafeBrowsingUIManager::UnsafeResource> unsafe_resource_;
 
   DISALLOW_COPY_AND_ASSIGN(ClientSideDetectionHost);
 };
 
 }  // namespace safe_browsing
 
 #endif  // CHROME_BROWSER_SAFE_BROWSING_CLIENT_SIDE_DETECTION_HOST_H_