[Media Router] Make MRUIService dispose its dependencies on MRMojoImpl in Shutdown()

chrome/browser/media/router/media_router_ui_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_MEDIA_ROUTER_MEDIA_ROUTER_UI_SERVICE_H_
 #define CHROME_BROWSER_MEDIA_ROUTER_MEDIA_ROUTER_UI_SERVICE_H_
 
 #include <memory>
 
 #include "chrome/browser/ui/toolbar/media_router_action_controller.h"
 #include "components/keyed_service/core/keyed_service.h"
 
 class Profile;
 
 namespace media_router {
 
 // Service that owns per-profile Media Router UI objects, such as the controller
 // for the Media Router toolbar action.
 class MediaRouterUIService : public KeyedService {
  public:
   explicit MediaRouterUIService(Profile* profile);
   ~MediaRouterUIService() override;
 
+  // KeyedService:
+  void Shutdown() override;
+
   static MediaRouterUIService* Get(Profile* profile);
 
   virtual MediaRouterActionController* action_controller();
 
  private:
   friend class MediaRouterUIBrowserTest;
 
-  MediaRouterActionController action_controller_;
+  std::unique_ptr<MediaRouterActionController> action_controller_;
 
   DISALLOW_COPY_AND_ASSIGN(MediaRouterUIService);
 };
 
 }  // namespace media_router
 
 #endif  // CHROME_BROWSER_MEDIA_ROUTER_MEDIA_ROUTER_UI_SERVICE_H_