[Media Router] Notify MRUI of a media status update when it starts observing

chrome/browser/ui/webui/media_router/media_router_ui.h

 // Copyright 2015 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_UI_WEBUI_MEDIA_ROUTER_MEDIA_ROUTER_UI_H_
 #define CHROME_BROWSER_UI_WEBUI_MEDIA_ROUTER_MEDIA_ROUTER_UI_H_
 
 #include <memory>
 #include <set>
 #include <string>
@@ skipping 184 matching lines @@
   FRIEND_TEST_ALL_PREFIXES(MediaRouterUITest,
                            GetExtensionNameEmptyWhenNotInstalled);
   FRIEND_TEST_ALL_PREFIXES(MediaRouterUITest,
                            GetExtensionNameEmptyWhenNotExtensionURL);
   FRIEND_TEST_ALL_PREFIXES(MediaRouterUITest,
                            RouteCreationTimeoutForPresentation);
   FRIEND_TEST_ALL_PREFIXES(MediaRouterUITest, RouteRequestFromIncognito);
   FRIEND_TEST_ALL_PREFIXES(MediaRouterUITest, OpenAndCloseUIDetailsView);
   FRIEND_TEST_ALL_PREFIXES(MediaRouterUITest, SendMediaCommands);
   FRIEND_TEST_ALL_PREFIXES(MediaRouterUITest, SendMediaStatusUpdate);
+  FRIEND_TEST_ALL_PREFIXES(MediaRouterUITest, SendInitialMediaStatusUpdate);
 
   class UIIssuesObserver;
 
   class UIMediaRoutesObserver : public MediaRoutesObserver {
    public:
     using RoutesUpdatedCallback =
         base::Callback<void(const std::vector<MediaRoute>&,
                             const std::vector<MediaRoute::Id>&)>;
     UIMediaRoutesObserver(MediaRouter* router,
                           const MediaSource::Id& source_id,
@@ skipping 180 matching lines @@
   // NOTE: Weak pointers must be invalidated before all other member variables.
   // Therefore |weak_factory_| must be placed at the end.
   base::WeakPtrFactory<MediaRouterUI> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(MediaRouterUI);
 };
 
 }  // namespace media_router
 
 #endif  // CHROME_BROWSER_UI_WEBUI_MEDIA_ROUTER_MEDIA_ROUTER_UI_H_