Moving ProfileDestroyer from ref counting to WeakPtr.

chrome/browser/profiles/profile_destroyer.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_PROFILES_PROFILE_DESTROYER_H_
 #define CHROME_BROWSER_PROFILES_PROFILE_DESTROYER_H_
 
 #include <vector>
 
 #include "base/memory/ref_counted.h"
 #include "base/timer.h"
 #include "content/public/browser/notification_observer.h"
 #include "content/public/browser/notification_registrar.h"
 
 class Profile;
 namespace content {
 class RenderProcessHost;
 }
 
 // We use this class to destroy the off the record profile so that we can make
 // sure it gets done asynchronously after all render process hosts are gone.
 class ProfileDestroyer
-    : public content::NotificationObserver,
-      public base::RefCounted<ProfileDestroyer> {
+    : public content::NotificationObserver {
  public:
   static void DestroyProfileWhenAppropriate(Profile* const profile);
   static void DestroyOffTheRecordProfileNow(Profile* const profile);
 
  private:
   friend class base::RefCounted<ProfileDestroyer>;
 
   ProfileDestroyer(
       Profile* const profile,
       const std::vector<content::RenderProcessHost*>& hosts);
@@ skipping 19 matching lines @@
   content::NotificationRegistrar registrar_;
 
   // We don't want to wait forever, so we have a cancellation timer.
   base::Timer timer_;
 
   // Used to count down the number of render process host left.
   uint32 num_hosts_;
 
   Profile* profile_;
 
+  base::WeakPtrFactory<ProfileDestroyer> weak_ptr_factory_;
+
   DISALLOW_COPY_AND_ASSIGN(ProfileDestroyer);
 };
 
 #endif  // CHROME_BROWSER_PROFILES_PROFILE_DESTROYER_H_