[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 62e132b8ccc9d1bf6106cdc9a72882ac1646af62..91cae709091fe5e8e95c1660da7ee28fe03b6a24 100644
--- a/chrome/browser/media/android/router/media_router_android.cc
+++ b/chrome/browser/media/android/router/media_router_android.cc
@@ -355,8 +355,8 @@ void MediaRouterAndroid::OnRouteCreated(
                    jis_local, std::string(),
                    true);  // TODO(avayvod): Populate for_display.
 
-  std::unique_ptr<RouteRequestResult> result = RouteRequestResult::FromSuccess(
-      base::MakeUnique<MediaRoute>(route), request->presentation_id);
+  std::unique_ptr<RouteRequestResult> result =
+      RouteRequestResult::FromSuccess(route, request->presentation_id);
   for (const MediaRouteResponseCallback& callback : request->callbacks)
     callback.Run(*result);