Make ExtensionContentSettingsStore refcounted.

chrome/browser/content_settings/host_content_settings_map.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.
 
 // Maps hostnames to custom content settings.  Written on the UI thread and read
 // on any thread.  One instance per profile.
 
 #ifndef CHROME_BROWSER_CONTENT_SETTINGS_HOST_CONTENT_SETTINGS_MAP_H_
 #define CHROME_BROWSER_CONTENT_SETTINGS_HOST_CONTENT_SETTINGS_MAP_H_
 #pragma once
@@ skipping 168 matching lines @@
   void SetBlockThirdPartyCookies(bool block);
 
   // Resets all settings levels.
   //
   // This should only be called on the UI thread.
   void ResetToDefaults();
 
   // Returns true if the default setting for the |content_type| is managed.
   bool IsDefaultContentSettingManaged(ContentSettingsType content_type) const;
 
+  // Detaches the HostContentSettingsMap from all Profile-related objects like
+  // PrefService. This methods needs to be called before destroying the Profile.
+  // Afterwards, none of the methods above that should only be called on the UI
+  // thread should be called anymore.
+  void ShutdownOnUIThread();
+
   // NotificationObserver implementation.
   virtual void Observe(NotificationType type,
                        const NotificationSource& source,
                        const NotificationDetails& details);
 
  private:
   friend struct BrowserThread::DeleteOnThread<BrowserThread::UI>;
   friend class DeleteTask<HostContentSettingsMap>;
 
   virtual ~HostContentSettingsMap();
@@ skipping 35 matching lines @@
   mutable base::Lock lock_;
 
   // Misc global settings.
   bool block_third_party_cookies_;
   bool is_block_third_party_cookies_managed_;
 
   DISALLOW_COPY_AND_ASSIGN(HostContentSettingsMap);
 };
 
 #endif  // CHROME_BROWSER_CONTENT_SETTINGS_HOST_CONTENT_SETTINGS_MAP_H_