Use native async/await support in pub.

sdk/lib/_internal/pub_generated/test/barback/all_includes_all_default_directories_test.dart

-// Copyright (c) 2014, 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.
-
-import 'package:scheduled_test/scheduled_test.dart';
-
-import '../descriptor.dart' as d;
-import '../serve/utils.dart';
-import '../test_pub.dart';
-
-main() {
-  initConfig();
-
-  setUp(() {
-    d.dir(
-        appPath,
-        [
-            d.appPubspec(),
-            d.dir('benchmark', [d.file('file.txt', 'benchmark')]),
-            d.dir('bin', [d.file('file.txt', 'bin')]),
-            d.dir('example', [d.file('file.txt', 'example')]),
-            d.dir('test', [d.file('file.txt', 'test')]),
-            d.dir('web', [d.file('file.txt', 'web')]),
-            d.dir('unknown', [d.file('file.txt', 'unknown')])]).create();
-  });
-
-  integration("build --all finds assets in default source directories", () {
-    schedulePub(
-        args: ["build", "--all"],
-        output: new RegExp(r'Built 5 files to "build".'));
-
-    d.dir(
-        appPath,
-        [
-            d.dir(
-                'build',
-                [
-                    d.dir('benchmark', [d.file('file.txt', 'benchmark')]),
-                    d.dir('bin', [d.file('file.txt', 'bin')]),
-                    d.dir('example', [d.file('file.txt', 'example')]),
-                    d.dir('test', [d.file('file.txt', 'test')]),
-                    d.dir('web', [d.file('file.txt', 'web')]),
-                    // Only includes default source directories.
-        d.nothing('unknown')])]).validate();
-  });
-
-  integration("serve --all finds assets in default source directories", () {
-    pubServe(args: ["--all"]);
-
-    requestShouldSucceed("file.txt", "benchmark", root: "benchmark");
-    requestShouldSucceed("file.txt", "bin", root: "bin");
-    requestShouldSucceed("file.txt", "example", root: "example");
-    requestShouldSucceed("file.txt", "test", root: "test");
-    requestShouldSucceed("file.txt", "web", root: "web");
-
-    expectNotServed("unknown");
-
-    endPubServe();
-  });
-}