Remove unused method in the native display service

chrome/browser/notifications/native_notification_display_service.h

 // Copyright 2016 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_NOTIFICATIONS_NATIVE_NOTIFICATION_DISPLAY_SERVICE_H_
 #define CHROME_BROWSER_NOTIFICATIONS_NATIVE_NOTIFICATION_DISPLAY_SERVICE_H_
 
 #include <map>
 #include <memory>
 #include <queue>
@@ skipping 38 matching lines @@
                                     NotificationCommon::Type notification_type,
                                     const std::string& origin,
                                     const std::string& notification_id,
                                     int action_index,
                                     const base::NullableString16& reply);
 
   // Registers an implementation object to handle notification operations
   // for |notification_type|.
   void AddNotificationHandler(NotificationCommon::Type notification_type,
                               std::unique_ptr<NotificationHandler> handler);
-
-  // Removes an implementation added via |AddNotificationHandler|.
-  void RemoveNotificationHandler(NotificationCommon::Type notification_type);
-
  private:
   NotificationHandler* GetNotificationHandler(
       NotificationCommon::Type notification_type);
 
   // Called by |notification_bridge_| when it is finished
   // initializing.  |success| indicates it is ready to be used.
   void OnNotificationPlatformBridgeReady(bool success);
 
   Profile* profile_;
 
@@ skipping 11 matching lines @@
 
   std::map<NotificationCommon::Type, std::unique_ptr<NotificationHandler>>
       notification_handlers_;
 
   base::WeakPtrFactory<NativeNotificationDisplayService> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(NativeNotificationDisplayService);
 };
 
 #endif  // CHROME_BROWSER_NOTIFICATIONS_NATIVE_NOTIFICATION_DISPLAY_SERVICE_H_