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

sdk/lib/_internal/pub_generated/test/get/git/check_out_revision_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.
 
 library pub_tests;
 
 import '../../descriptor.dart' as d;
 import '../../test_pub.dart';
 
 main() {
   initConfig();
   integration('checks out a package at a specific revision from Git', () {
     ensureGit();
 
-    var repo = d.git('foo.git', [
-      d.libDir('foo', 'foo 1'),
-      d.libPubspec('foo', '1.0.0')
-    ]);
+    var repo =
+        d.git('foo.git', [d.libDir('foo', 'foo 1'), d.libPubspec('foo', '1.0.0')]);
     repo.create();
     var commit = repo.revParse('HEAD');
 
-    d.git('foo.git', [
-      d.libDir('foo', 'foo 2'),
-      d.libPubspec('foo', '1.0.0')
-    ]).commit();
+    d.git(
+        'foo.git',
+        [d.libDir('foo', 'foo 2'), d.libPubspec('foo', '1.0.0')]).commit();
 
     d.appDir({
-      "foo": {"git": {"url": "../foo.git", "ref": commit}}
+      "foo": {
+        "git": {
+          "url": "../foo.git",
+          "ref": commit
+        }
+      }
     }).create();
 
     pubGet();
 
-    d.dir(packagesPath, [
-      d.dir('foo', [
-        d.file('foo.dart', 'main() => "foo 1";')
-      ])
-    ]).validate();
+    d.dir(
+        packagesPath,
+        [d.dir('foo', [d.file('foo.dart', 'main() => "foo 1";')])]).validate();
   });
 }