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

sdk/lib/_internal/pub_generated/test/dart2js/passes_along_environment_constants_test.dart

 // Copyright (c) 2013, 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.
 
 import 'package:scheduled_test/scheduled_test.dart';
 
 import '../descriptor.dart' as d;
 import '../test_pub.dart';
 import '../serve/utils.dart';
 
 main() {
   initConfig();
   integration("passes along environment constants", () {
-    d.dir(appPath, [
-      d.pubspec({
+    d.dir(appPath, [d.pubspec({
         "name": "myapp",
         "transformers": [{
-          "\$dart2js": {"environment": {'CONSTANT': 'true'}}
-        }]
-      }),
-      d.dir("web", [
-        d.file("main.dart", """
+            "\$dart2js": {
+              "environment": {
+                'CONSTANT': 'true'
+              }
+            }
+          }]
+      }), d.dir("web", [d.file("main.dart", """
 void main() {
   if (const bool.fromEnvironment('CONSTANT')) {
     print("hello");
   }
 }
-""")
-      ])
-    ]).create();
+""")])]).create();
 
     pubServe();
     requestShouldSucceed("main.dart.js", contains("hello"));
     endPubServe();
   });
 }