Show Media Router toolbar icon ephemerally for MR dialogs

chrome/browser/media/router/media_router_ui_service.cc

 // 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.
 
 #include "chrome/browser/media/router/media_router_ui_service.h"
 
 #include "chrome/browser/media/router/media_router_feature.h"
 #include "chrome/browser/media/router/media_router_ui_service_factory.h"
 #include "chrome/browser/profiles/profile.h"
 
 namespace media_router {
 
 MediaRouterUIService::MediaRouterUIService(Profile* profile)
-    : action_controller_(profile) {}
+    : action_controller_(
+          base::MakeUnique<MediaRouterActionController>(profile)) {}
 
 MediaRouterUIService::~MediaRouterUIService() {}
 
 // static
 MediaRouterUIService* MediaRouterUIService::Get(Profile* profile) {
   return MediaRouterUIServiceFactory::GetForBrowserContext(profile);
 }
 
+MediaRouterActionController* MediaRouterUIService::action_controller() const {
+  return action_controller_.get();
+}
+
 }  // namespace media_router