[Media Router] Use DialMediaSinkService in MediaRouterMojoImpl

chrome/browser/media/router/media_router_feature.cc

 // Copyright 2015 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/media/router/media_router_feature.h"
 
+#include "base/feature_list.h"
 #include "build/build_config.h"
 #include "content/public/browser/browser_context.h"
 #include "extensions/features/features.h"
 
 #if defined(OS_ANDROID) || BUILDFLAG(ENABLE_EXTENSIONS)
 #include "chrome/common/pref_names.h"
 #include "components/prefs/pref_service.h"
 #include "components/user_prefs/user_prefs.h"
 #endif  // defined(OS_ANDROID) || BUILDFLAG(ENABLE_EXTENSIONS)
 
 namespace media_router {
 
+#if !defined(OS_ANDROID)
+// Controls if browser side DIAL device discovery is enabled.
+const base::Feature kEnableDialLocalDiscovery{

[Kevin M, 2017/05/08 18:22:19]

Class-typed variables (like Feature) cannot have static storage duration; they
can't be used as kConstants.

https://google.github.io/styleguide/cppguide.html#Static_and_Global_Variables

[zhaobin, 2017/05/08 20:13:48]

chrome_features.cc uses it this way...
https://cs.chromium.org/chromium/src/chrome/common/chrome_features.cc?rcl=5ca...

+    "EnableDialLocalDiscovery", base::FEATURE_DISABLED_BY_DEFAULT};
+
+// Controls if browser side Cast device discovery is enabled.
+const base::Feature kEnableCastDiscovery{"EnableCastDiscovery",
+                                         base::FEATURE_DISABLED_BY_DEFAULT};
+#endif
+
 #if defined(OS_ANDROID) || BUILDFLAG(ENABLE_EXTENSIONS)
 namespace {
 const PrefService::Preference* GetMediaRouterPref(
     content::BrowserContext* context) {
   return user_prefs::UserPrefs::Get(context)
       ->FindPreference(prefs::kEnableMediaRouter);
 }
 }  // namespace
 #endif  // defined(OS_ANDROID) || BUILDFLAG(ENABLE_EXTENSIONS)
 
 bool MediaRouterEnabled(content::BrowserContext* context) {
 #if defined(OS_ANDROID) || BUILDFLAG(ENABLE_EXTENSIONS)
   const PrefService::Preference* pref = GetMediaRouterPref(context);
   // Only use the pref value if it set from a mandatory policy.
   if (pref->IsManaged() && !pref->IsDefaultValue()) {
     bool allowed = false;
     CHECK(pref->GetValue()->GetAsBoolean(&allowed));
     return allowed;
   }
   return true;
 #else  // !(defined(OS_ANDROID) || BUILDFLAG(ENABLE_EXTENSIONS))
   return false;
 #endif  // defined(OS_ANDROID) || BUILDFLAG(ENABLE_EXTENSIONS)
 }
 
+#if !defined(OS_ANDROID)
+// Returns true if browser side DIAL discovery is enabled.
+bool DialLocalDiscoveryEnabled() {
+  return base::FeatureList::IsEnabled(kEnableDialLocalDiscovery);
+}
+
+// Returns true if browser side Cast discovery is enabled.
+bool CastDiscoveryEnabled() {
+  return base::FeatureList::IsEnabled(kEnableCastDiscovery);
+}
+#endif
+
 }  // namespace media_router