[Media Router] Enable MR by default now that it is at 100% in stable.

chrome/browser/extensions/extension_context_menu_model_unittest.cc

 // Copyright (c) 2012 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/extensions/extension_context_menu_model.h"
 
 #include <utility>
 
 #include "base/macros.h"
 #include "base/memory/ptr_util.h"
@@ skipping 324 matching lines @@
 
   // We shouldn't go above the limit of top-level items.
   EXPECT_EQ(api::context_menus::ACTION_MENU_TOP_LEVEL_LIMIT,
             CountExtensionItems(*builder.BuildMenu()));
 }
 
 // Test that the "show" and "hide" menu items appear correctly in the extension
 // context menu without the toolbar redesign.
 TEST_F(ExtensionContextMenuModelTest, ExtensionContextMenuShowAndHideLegacy) {
   // Start with the toolbar redesign disabled.
-  std::unique_ptr<FeatureSwitch::ScopedOverride> toolbar_redesign_override(
-      new FeatureSwitch::ScopedOverride(
-          FeatureSwitch::extension_action_redesign(), false));
+  // Disable Media Router first, since Extension Action Redesign would be force

[Devlin, 2016/09/08 22:03:13]

It might be out of scope for this change, but can we remove the logic to link
these switches now that they are both default-enabled?

[imcheng, 2016/09/09 16:51:24]

Sure, it should be a pretty small and harmless change (now that both are enabled
by default)

+  // enabled otherwise.
+  FeatureSwitch::ScopedOverride enable_media_router(
+      extensions::FeatureSwitch::media_router(), false);
+  FeatureSwitch::ScopedOverride toolbar_redesign_override(
+      FeatureSwitch::extension_action_redesign(), false);
 
   InitializeEmptyExtensionService();
   Browser* browser = GetBrowser();
   extension_action_test_util::CreateToolbarModelForProfile(profile());
 
   const Extension* page_action = AddExtension(
       "page_action_extension", manifest_keys::kPageAction, Manifest::INTERNAL);
   const Extension* browser_action =
       AddExtension("browser_action_extension", manifest_keys::kBrowserAction,
                    Manifest::INTERNAL);
@@ skipping 349 matching lines @@
         "no_action", nullptr, Manifest::INTERNAL);
     ExtensionContextMenuModel menu(no_action, GetBrowser(),
                                    ExtensionContextMenuModel::VISIBLE, nullptr);
     int inspect_popup_index =
         menu.GetIndexOfCommandId(ExtensionContextMenuModel::INSPECT_POPUP);
     EXPECT_EQ(-1, inspect_popup_index);
   }
 }
 
 }  // namespace extensions