[Media Router] Convert to use typemaps for media_router.mojom.

chrome/browser/media/android/router/media_router_android.cc

Index: chrome/browser/media/android/router/media_router_android.cc
diff --git a/chrome/browser/media/android/router/media_router_android.cc b/chrome/browser/media/android/router/media_router_android.cc
index 9fa7aa64f3a124c44ee96637a4077b5033f4ddf9..45ec594df210b4c67eb5982de2650368dea85f0d 100644
--- a/chrome/browser/media/android/router/media_router_android.cc
+++ b/chrome/browser/media/android/router/media_router_android.cc
@@ -370,7 +370,7 @@ void MediaRouterAndroid::OnRouteCreated(
                    true);  // TODO(avayvod): Populate for_display.
 
   std::unique_ptr<RouteRequestResult> result = RouteRequestResult::FromSuccess(
-      base::MakeUnique<MediaRoute>(route), request->presentation_id);
+      route, request->presentation_id);
   for (const MediaRouteResponseCallback& callback : request->callbacks)
     callback.Run(*result);