[Media Router] Remove the EnableDialLocalDiscovery feature.

The feature is default enabled in crrev.com/c/794715.

Next step is to remove extension-side DIAL discovery logic.

Bug: 718154
Change-Id: I67569a9a4acf0a68c461307592b229c5b91e45d1
Reviewed-on: https://chromium-review.googlesource.com/809925
Commit-Queue: Derek Cheng <imcheng@chromium.org>
Reviewed-by: mark a. foltz <mfoltz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#523567}

chrome/browser/media/router/media_router_feature.cc

@@ -19,10 +19,6 @@
 namespace media_router {
 
 #if !defined(OS_ANDROID)
-// Controls if browser side DIAL device discovery is enabled.
-const base::Feature kEnableDialLocalDiscovery{"EnableDialLocalDiscovery",
-                                              base::FEATURE_ENABLED_BY_DEFAULT};
-
 // Controls if browser side Cast device discovery is enabled.
 const base::Feature kEnableCastDiscovery{"EnableCastDiscovery",
                                          base::FEATURE_DISABLED_BY_DEFAULT};
@@ -61,11 +57,6 @@ bool MediaRouterEnabled(content::BrowserContext* context) {
 }
 
 #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);
@@ -75,7 +66,6 @@ bool CastDiscoveryEnabled() {
 bool CastLocalMediaEnabled() {
   return base::FeatureList::IsEnabled(kEnableCastLocalMedia);
 }
-
 #endif
 
 }  // namespace media_router

chrome/browser/media/router/mojo/media_router_desktop.cc

@@ -95,7 +95,6 @@ void MediaRouterDesktop::RegisterMediaRouteProvider(
   // Enabling browser side discovery means disabling extension side discovery.
   // We are migrating discovery from the external Media Route Provider to the
   // Media Router (crbug.com/687383), so we need to disable it in the provider.
-  config->enable_dial_discovery = !media_router::DialLocalDiscoveryEnabled();
   config->enable_cast_discovery = !media_router::CastDiscoveryEnabled();
   std::move(callback).Run(instance_id(), std::move(config));
 
@@ -166,7 +165,6 @@ void MediaRouterDesktop::StartDiscovery() {
     }
   }
 
-  if (media_router::DialLocalDiscoveryEnabled()) {
   if (!dial_media_sink_service_) {
     dial_media_sink_service_ =
         std::make_unique<DialMediaSinkService>(context());
@@ -174,8 +172,7 @@ void MediaRouterDesktop::StartDiscovery() {
     OnDialSinkAddedCallback dial_sink_added_cb;
     scoped_refptr<base::SequencedTaskRunner> dial_sink_added_cb_sequence;
     if (cast_media_sink_service_) {
-        dial_sink_added_cb =
-            cast_media_sink_service_->GetDialSinkAddedCallback();
+      dial_sink_added_cb = cast_media_sink_service_->GetDialSinkAddedCallback();
       dial_sink_added_cb_sequence =
           cast_media_sink_service_->GetImplTaskRunner();
     }
@@ -186,7 +183,6 @@ void MediaRouterDesktop::StartDiscovery() {
   } else {
     dial_media_sink_service_->ForceSinkDiscoveryCallback();
   }
-  }
 }
 
 void MediaRouterDesktop::ProvideSinks(const std::string& provider_name,

chrome/browser/media/router/mojo/media_router_desktop_unittest.cc

@@ -83,10 +83,10 @@ class MediaRouterDesktopTest : public MediaRouterMojoTest {
 
  protected:
   void SetUp() override {
-    feature_list_.InitWithFeatures(
-        {kEnableDialLocalDiscovery, kEnableCastDiscovery}, {});
+    feature_list_.InitWithFeatures({kEnableCastDiscovery}, {});
     MediaRouterMojoTest::SetUp();
   }
+
   std::unique_ptr<MediaRouterMojoImpl> CreateMediaRouter() override {
     auto dial_media_sink_service =
         std::make_unique<MockDialMediaSinkService>(profile());