Detach the dependency from host_content_settings_map to extension.

chrome/browser/content_settings/content_settings_custom_extension_provider.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_CONTENT_SETTINGS_CONTENT_SETTINGS_CUSTOM_EXTENSION_PROVIDER_H_
 #define CHROME_BROWSER_CONTENT_SETTINGS_CONTENT_SETTINGS_CUSTOM_EXTENSION_PROVIDER_H_
 
 #include <string>
 
 #include "base/memory/ref_counted.h"
@@ skipping 23 matching lines @@
       const ContentSettingsPattern& secondary_pattern,
       ContentSettingsType content_type,
       const ResourceIdentifier& resource_identifier,
       base::Value* value) OVERRIDE;
 
   virtual void ClearAllContentSettingsRules(ContentSettingsType content_type)
       OVERRIDE {}
 
   virtual void ShutdownOnUIThread() OVERRIDE;
 
+  virtual std::string GetProviderName() const OVERRIDE;
+
+  virtual SettingSource GetSettingSource() const OVERRIDE;
+
   // extensions::ContentSettingsStore::Observer methods:
   virtual void OnContentSettingChanged(const std::string& extension_id,
                                        bool incognito) OVERRIDE;
 
  private:
   // Specifies whether this provider manages settings for incognito or regular
   // sessions.
   bool incognito_;
 
   // The backend storing content setting rules defined by extensions.
   scoped_refptr<extensions::ContentSettingsStore> extensions_settings_;
 
   DISALLOW_COPY_AND_ASSIGN(CustomExtensionProvider);
 };
 
 }  // namespace content_settings
 
 #endif  // CHROME_BROWSER_CONTENT_SETTINGS_CONTENT_SETTINGS_CUSTOM_EXTENSION_PROVIDER_H_