Correct ENABLE_MEDIA_ROUTER defines to fix compilation without it.

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/lazy_instance.h"
 #include "chrome/browser/ui/toolbar/media_router_action.h"
 #include "chrome/browser/ui/toolbar/toolbar_action_view_controller.h"
 #include "extensions/common/feature_switch.h"
@@ skipping 25 matching lines @@
   // designed for the new toolbar.
   if (!extensions::FeatureSwitch::extension_action_redesign()->IsEnabled())
     return component_actions.Pass();
 
   // Add component toolbar actions here.
   // This current design means that the ComponentToolbarActionsFactory is aware
   // of all actions. Since we should *not* have an excessive amount of these
   // (since each will have an action in the toolbar or overflow menu), this
   // should be okay. If this changes, we should rethink this design to have,
   // e.g., RegisterChromeAction().
+#if defined(ENABLE_MEDIA_ROUTER)
   if (media_router_ui_enabled_)
     component_actions.push_back(new MediaRouterAction());
+#endif  // defined(ENABLE_MEDIA_ROUTER)
 
   return component_actions.Pass();
 }
 
 int ComponentToolbarActionsFactory::GetNumComponentActions() {
   if (num_component_actions_ == -1)
     num_component_actions_ = GetComponentToolbarActions().size();
 
   return num_component_actions_;
 }
 
 // static
 void ComponentToolbarActionsFactory::SetTestingFactory(
     ComponentToolbarActionsFactory* factory) {
   testing_factory_ = factory;
 }