Show Media Router toolbar icon ephemerally for MR dialogs

chrome/browser/media/router/media_router_ui_service.cc

Index: chrome/browser/media/router/media_router_ui_service.cc
diff --git a/chrome/browser/media/router/media_router_ui_service.cc b/chrome/browser/media/router/media_router_ui_service.cc
index 98cb3e60a05c9432dac08b67bf3361be05388084..a473e1e5abad8390e46e717b64904a588b411df7 100644
--- a/chrome/browser/media/router/media_router_ui_service.cc
+++ b/chrome/browser/media/router/media_router_ui_service.cc
@@ -20,4 +20,8 @@ MediaRouterUIService* MediaRouterUIService::Get(Profile* profile) {
   return MediaRouterUIServiceFactory::GetForBrowserContext(profile);
 }
 
+MediaRouterActionController* MediaRouterUIService::action_controller() {
+  return &action_controller_;
+}
+
 }  // namespace media_router