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

sdk/lib/_internal/pub_generated/test/transformer/asset_not_found_exceptions_are_detectable_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 'dart:convert';
 
 import 'package:scheduled_test/scheduled_stream.dart';
 
@@ skipping 23 matching lines @@
       })));
     });
   }
 }
 """;
 
 main() {
   initConfig();
   withBarbackVersions("any", () {
     integration("AssetNotFoundExceptions are detectable", () {
-      d.dir(appPath, [
-        d.pubspec({
+      d.dir(appPath, [d.pubspec({
           "name": "myapp",
           "transformers": ["myapp/src/transformer"]
         }),
-        d.dir("lib", [d.dir("src", [
-          d.file("transformer.dart", transformer)
-        ])]),
-        d.dir("web", [
-          d.file("foo.txt", "foo")
-        ])
-      ]).create();
+            d.dir("lib", [d.dir("src", [d.file("transformer.dart", transformer)])]),
+            d.dir("web", [d.file("foo.txt", "foo")])]).create();
 
       createLockFile('myapp', pkg: ['barback']);
 
       var server = pubServe();
       requestShouldSucceed("foo.txt", JSON.encode({
         "package": "myapp",
         "path": "nonexistent"
       }));
       endPubServe();
 
       // Since the AssetNotFoundException was caught and handled, the server
       // shouldn't print any error information for it.
       server.stderr.expect(isDone);
     });
   });
 }