Add Provider ID to MediaSinks discovered in browser

Set the provider ID for Cast/Dial sinks discovered in browser, so that it's not UNKNOWN.
We will remove UNKNOWN as the default argument for the ctor param in a separate patch to avoid bugs like this.

Bug: 792586
Change-Id: Ia43a3e451908f8a8e3c902b7869196f2ff6a7b2a
Reviewed-on: https://chromium-review.googlesource.com/811666Reviewed-by: Derek Cheng <imcheng@chromium.org>
Commit-Queue: Takumi Fujimoto <takumif@chromium.org>
Cr-Commit-Position: refs/heads/master@{#522194}

chrome/browser/media/router/discovery/dial/dial_media_sink_service_impl.cc

@@ -115,7 +115,7 @@ void DialMediaSinkServiceImpl::OnDeviceDescriptionAvailable(
   // ID when it is sent to the extension, because it derives a different sink ID
   // using the given sink ID.
   MediaSink sink(description_data.unique_id, description_data.friendly_name,
-                 SinkIconType::GENERIC);
+                 SinkIconType::GENERIC, MediaRouteProviderId::EXTENSION);
   DialSinkExtraData extra_data;
   extra_data.app_url = description_data.app_url;
   extra_data.model_name = description_data.model_name;

chrome/browser/media/router/discovery/mdns/cast_media_sink_service.cc

@@ -64,7 +64,8 @@ ErrorType CreateCastMediaSink(const DnsSdService& service,
   std::string friendly_name = service_data["fn"];
   if (friendly_name.empty())
     return ErrorType::MISSING_FRIENDLY_NAME;
-  MediaSink sink(unique_id, friendly_name, SinkIconType::CAST);
+  MediaSink sink(unique_id, friendly_name, SinkIconType::CAST,
+                 MediaRouteProviderId::EXTENSION);
 
   CastSinkExtraData extra_data;
   extra_data.ip_endpoint =

chrome/browser/media/router/discovery/mdns/cast_media_sink_service_impl.cc

@@ -30,7 +30,8 @@ media_router::MediaSinkInternal CreateCastSinkFromDialSink(
   const std::string& unique_id = dial_sink.sink().id();
   const std::string& friendly_name = dial_sink.sink().name();
   media_router::MediaSink sink(unique_id, friendly_name,
-                               media_router::SinkIconType::CAST);
+                               media_router::SinkIconType::CAST,
+                               media_router::MediaRouteProviderId::EXTENSION);
 
   media_router::CastSinkExtraData extra_data;
   extra_data.ip_endpoint =