Media Remoting: Add mojo interfaces between browser and extension.

chrome/browser/media/router/mojo/media_router_mojo_impl.h

Index: chrome/browser/media/router/mojo/media_router_mojo_impl.h
diff --git a/chrome/browser/media/router/mojo/media_router_mojo_impl.h b/chrome/browser/media/router/mojo/media_router_mojo_impl.h
index d1c6c00cdabf348dc77501b77c1ab34bf00674c3..a0473c42f4f37957b3ead477ef887388050e7c37 100644
--- a/chrome/browser/media/router/mojo/media_router_mojo_impl.h
+++ b/chrome/browser/media/router/mojo/media_router_mojo_impl.h
@@ -342,6 +342,10 @@ class MediaRouterMojoImpl : public MediaRouterBase,
   void OnRouteMessagesReceived(
       const std::string& route_id,
       const std::vector<RouteMessage>& messages) override;
+  void OnMediaRemoterCreated(
+      int32_t tab_id,
+      media::mojom::MirrorServiceRemoterPtr remoter,
+      media::mojom::MirrorServiceRemotingSourceRequest source_request) override;
 
   // Result callback when Mojo terminateRoute is invoked.  |route_id| is bound
   // to the ID of the route that was terminated.