[Media Router] Add ProvideSinks() Mojo API

chrome/browser/media/router/mock_media_router.h

Index: chrome/browser/media/router/mock_media_router.h
diff --git a/chrome/browser/media/router/mock_media_router.h b/chrome/browser/media/router/mock_media_router.h
index f2d6ae4f3609af5601059d20498fcadf216b2b08..a27c66483e9b04bfb505efe65449fcd970a107a0 100644
--- a/chrome/browser/media/router/mock_media_router.h
+++ b/chrome/browser/media/router/mock_media_router.h
@@ -75,6 +75,10 @@ class MockMediaRouter : public MediaRouterBase {
            const std::string& search_input,
            const std::string& domain,
            const MediaSinkSearchResponseCallback& sink_callback));
+  void OnSinksDiscovered(std::unique_ptr<MediaSinkList> sinks) override {
+    OnSinksDiscoveredInternal(sinks.get());
+  }
+  MOCK_METHOD1(OnSinksDiscoveredInternal, void(MediaSinkList* sinks));
   MOCK_METHOD1(OnPresentationSessionDetached,
                void(const MediaRoute::Id& route_id));
   std::unique_ptr<PresentationConnectionStateSubscription>