Revert "Use native async/await support in pub."

sdk/lib/_internal/pub_generated/test/serve/web_socket/url_to_asset_id_errors_test.dart

 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS d.file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library pub_tests;
 
 import 'package:scheduled_test/scheduled_test.dart';
 
 import '../../descriptor.dart' as d;
 import '../../test_pub.dart';
 import '../utils.dart';
 
 main() {
   initConfig();
   setUp(() {
-    d.dir(appPath, [
-      d.appPubspec()
-    ]).create();
+    d.dir(appPath, [d.appPubspec()]).create();
   });
 
   integration("responds with NOT_SERVED for an unknown domain", () {
     pubServe();
     expectWebSocketError("urlToAssetId", {
       "url": "http://example.com:80/index.html"
     }, NOT_SERVED, '"example.com:80" is not being served by pub.');
     endPubServe();
   });
 
   integration("responds with NOT_SERVED for an unknown port", () {
     pubServe();
     expectWebSocketError("urlToAssetId", {
       "url": "http://localhost:80/index.html"
     }, NOT_SERVED, '"localhost:80" is not being served by pub.');
     endPubServe();
   });
-}
+}