Refactor notifications of chrome/browser/webdata

chrome/browser/api/webdata/web_data_service_base.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_API_WEBDATA_WEB_DATA_SERVICE_BASE_H_
 #define CHROME_BROWSER_API_WEBDATA_WEB_DATA_SERVICE_BASE_H_
 
-#include "content/public/browser/notification_source.h"
-
 // Base for WebDataService class hierarchy.
 class WebDataServiceBase {
  public:
   // All requests return an opaque handle of the following type.
   typedef int Handle;
 
   virtual ~WebDataServiceBase() {}
 
   // Cancel any pending request. You need to call this method if your
   // WebDataServiceConsumer is about to be deleted.
   virtual void CancelRequest(Handle h) = 0;
-
-  // Returns the notification source for this service. This may use a
-  // pointer other than this object's |this| pointer.
-  virtual content::NotificationSource GetNotificationSource() = 0;
 };
 
 #endif  // CHROME_BROWSER_API_WEBDATA_WEB_DATA_SERVICE_BASE_H_