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

sdk/lib/_internal/pub_generated/test/serve/invalid_urls_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.
 
 library pub_tests;
 
 import '../descriptor.dart' as d;
 import '../test_pub.dart';
 import 'utils.dart';
 
 main() {
   initConfig();
   integration("responds with a 404 on incomplete special URLs", () {
-    d.dir("foo", [
-      d.libPubspec("foo", "0.0.1")
-    ]).create();
+    d.dir("foo", [d.libPubspec("foo", "0.0.1")]).create();
 
-    d.dir(appPath, [
-      d.appPubspec({
-        "foo": {"path": "../foo"}
+    d.dir(appPath, [d.appPubspec({
+        "foo": {
+          "path": "../foo"
+        }
       }),
-      d.dir("lib", [
-        // Make a file that maps to the special "packages" directory to ensure
+          d.dir(
+              "lib",
+              [// Make a file that maps to the special "packages" directory to ensure
         // it is *not* found.
-        d.file("packages")
-      ]),
-      d.dir("web", [
-        d.file("packages")
-      ])
-    ]).create();
+        d.file("packages")]), d.dir("web", [d.file("packages")])]).create();
 
     pubGet();
     pubServe();
     requestShould404("packages");
     requestShould404("packages/");
     requestShould404("packages/myapp");
     requestShould404("packages/myapp/");
     requestShould404("packages/foo");
     requestShould404("packages/foo/");
     requestShould404("packages/unknown");
     requestShould404("packages/unknown/");
     endPubServe();
   });
 
 }