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

sdk/lib/_internal/pub_generated/test/build/outputs_error_to_json_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 '../../lib/src/exit_codes.dart' as exit_codes;
 import '../descriptor.dart' as d;
@@ skipping 14 matching lines @@
 """;
 
 main() {
   initConfig();
   withBarbackVersions("any", () {
     integration("outputs error to JSON in a failed build", () {
       // Loading transformers takes several seconds, so make sure we don't
       // timeout.
       currentSchedule.timeout *= 2;
 
-      d.dir(appPath, [
-        d.pubspec({
+      d.dir(appPath, [d.pubspec({
           "name": "myapp",
           "transformers": ["myapp"]
         }),
-        d.dir("lib", [
-          d.file("transformer.dart", TRANSFORMER)
-        ]),
-        d.dir("web", [
-          d.file("foo.txt", "foo")
-        ])
-      ]).create();
+            d.dir("lib", [d.file("transformer.dart", TRANSFORMER)]),
+            d.dir("web", [d.file("foo.txt", "foo")])]).create();
 
       createLockFile('myapp', pkg: ['barback']);
 
-      schedulePub(args: ["build", "--format", "json"],
-          outputJson: {
-            "buildResult": "failure",
-            "errors": [
-              {
-                "error": startsWith("Transform Rewrite on myapp|web/foo.txt "
-                    "threw error: oh no!")
-              }
-            ],
-            "log": []
-          },
-          exitCode: exit_codes.DATA);
+      schedulePub(args: ["build", "--format", "json"], outputJson: {
+        "buildResult": "failure",
+        "errors": [{
+            "error": startsWith(
+                "Transform Rewrite on myapp|web/foo.txt " "threw error: oh no!")
+          }],
+        "log": []
+      }, exitCode: exit_codes.DATA);
     });
   });
 }