[Media Router] Add experiment control logic.

chrome/browser/extensions/external_component_loader.cc

 // Copyright (c) 2013 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/external_component_loader.h"
 
 #include "base/command_line.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/extensions/component_extensions_whitelist/whitelist.h"
 #include "chrome/browser/search/hotword_service.h"
 #include "chrome/browser/search/hotword_service_factory.h"
 #include "chrome/browser/signin/signin_manager_factory.h"
 #include "chrome/common/chrome_switches.h"

[msw, 2015/10/23 20:18:42]

nit: remove

[imcheng, 2015/10/23 21:39:26]

Done.

 #include "chrome/common/extensions/extension_constants.h"
 #include "components/signin/core/browser/signin_manager.h"
 #include "extensions/common/extension_urls.h"
 #include "extensions/common/manifest.h"
 
 #if defined(OS_CHROMEOS)
 #include "base/command_line.h"
 #include "chromeos/chromeos_switches.h"
 #endif
 
 #if defined(ENABLE_APP_LIST) && defined(OS_CHROMEOS)
 #include "chrome/browser/ui/app_list/google_now_extension.h"
 #endif
 
+#if defined(ENABLE_MEDIA_ROUTER) && defined(GOOGLE_CHROME_BUILD)
+#include "chrome/browser/media/router/media_router_feature.h"
+#endif
+
 namespace extensions {
 
 ExternalComponentLoader::ExternalComponentLoader(Profile* profile)
     : profile_(profile) {
 }
 
 ExternalComponentLoader::~ExternalComponentLoader() {}
 
 void ExternalComponentLoader::StartLoading() {
   prefs_.reset(new base::DictionaryValue());
   AddExternalExtension(extension_misc::kInAppPaymentsSupportAppId);
 
   if (HotwordServiceFactory::IsHotwordAllowed(profile_))
     AddExternalExtension(extension_misc::kHotwordSharedModuleId);
 
 #if defined(OS_CHROMEOS)
   {
     base::CommandLine* const command_line =
         base::CommandLine::ForCurrentProcess();
     if (!command_line->HasSwitch(chromeos::switches::kDisableNewZIPUnpacker))
       AddExternalExtension(extension_misc::kZIPUnpackerExtensionId);
   }
 #endif
 
 #if defined(ENABLE_MEDIA_ROUTER) && defined(GOOGLE_CHROME_BUILD)

[msw, 2015/10/23 20:18:42]

Why don't other blocks check GOOGLE_CHROME_BUILD?

[imcheng, 2015/10/23 21:39:26]

The stable extension that would be downloaded here contains closed source
components. But for development purposes we can build the extension ourselves
and use it with Chromium and Media Router.

[msw, 2015/10/23 22:30:49]

Acknowledged.

-  if (switches::MediaRouterEnabled())
+  if (media_router::MediaRouterEnabled())
     AddExternalExtension(extension_misc::kMediaRouterStableExtensionId);
 #endif  // defined(ENABLE_MEDIA_ROUTER) && defined(GOOGLE_CHROME_BUILD)
 
 #if defined(ENABLE_APP_LIST) && defined(OS_CHROMEOS)
   std::string google_now_extension_id;
   if (GetGoogleNowExtensionId(&google_now_extension_id))
     AddExternalExtension(google_now_extension_id);
 #endif
 
   LoadFinished();
 }
 
 void ExternalComponentLoader::AddExternalExtension(
     const std::string& extension_id) {
   if (!IsComponentExtensionWhitelisted(extension_id))
     return;
 
   prefs_->SetString(extension_id + ".external_update_url",
                     extension_urls::GetWebstoreUpdateUrl().spec());
 }
 
 }  // namespace extensions