Show media router toolbar icon ephemerally for active local routes and issues

chrome/browser/ui/toolbar/component_toolbar_actions_factory.cc

 // Copyright 2014 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/ui/toolbar/component_toolbar_actions_factory.h"
 
 #include "base/command_line.h"
 #include "base/lazy_instance.h"
 #include "chrome/browser/extensions/component_migration_helper.h"
 #include "chrome/browser/media/router/media_router_feature.h"
+#include "chrome/browser/media/router/media_router_ui_service.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/toolbar/toolbar_action_view_controller.h"
 #include "extensions/common/feature_switch.h"
 
 #if defined(ENABLE_MEDIA_ROUTER)
 #include "chrome/browser/ui/toolbar/media_router_action.h"
 #endif
 
 namespace {
@@ skipping 66 matching lines @@
 void ComponentToolbarActionsFactory::HandleComponentMigrations(
     extensions::ComponentMigrationHelper* helper,
     Profile* profile) const {
   if (media_router::MediaRouterEnabled(profile)) {
     helper->OnFeatureEnabled(kMediaRouterActionId);
   } else {
     helper->OnFeatureDisabled(kMediaRouterActionId);
   }
 }
 
+void ComponentToolbarActionsFactory::InitializeComponentActionControllers(
+    Profile* profile) {
+  if (media_router::MediaRouterEnabled(profile))
+    media_router::MediaRouterUIService::Get(profile);

[Devlin, 2016/09/15 21:19:17]

Would this same effect be achieved by
KeyedServiceBasefactory::ServiceIsCreatedWithContext()?

[takumif, 2016/09/16 21:19:22]

Yes, using ServiceIsCreatedWithContext() (didn't know about it!) and
ServiceIsNULLWhileTesting() instead would work. I'll put those in the
MRUIServiceFactory once part 1 lands and that file gets created (I can't put it
in that CL since we can't instantiate MRUIService until this CL lands).

+}