Store the async-await compiled pub code directly in the repo.

sdk/lib/_internal/pub_generated/test/oauth2/with_no_credentials_authenticates_and_saves_credentials_test.dart

-// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS 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.
-
 import 'package:scheduled_test/scheduled_test.dart';
 import 'package:scheduled_test/scheduled_server.dart';
 import 'package:shelf/shelf.dart' as shelf;
-
 import '../descriptor.dart' as d;
 import '../test_pub.dart';
-
+import 'utils.dart';
 main() {
   initConfig();
-  integration('with a pre-existing credentials.json does not authenticate', () {
+  integration(
+      'with no credentials.json, authenticates and saves ' 'credentials.json',
+      () {
     d.validPackage.create();
-
     var server = new ScheduledServer();
-    d.credentialsFile(server, 'access token').create();
     var pub = startPublish(server);
     confirmPublish(pub);
-
+    authorizePub(pub, server);
     server.handle('GET', '/api/packages/versions/new', (request) {
-      expect(request.headers,
+      expect(
+          request.headers,
           containsPair('authorization', 'Bearer access token'));
-
       return new shelf.Response(200);
     });
-
-    pub.kill();
+    pub.shouldExit(1);
+    d.credentialsFile(server, 'access token').validate();
   });
-}
+}