Start pulling pub from its own repo.

sdk/lib/_internal/pub/test/dart2js/includes_source_maps_in_debug_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.
-
-import 'package:scheduled_test/scheduled_test.dart';
-
-import '../descriptor.dart' as d;
-import '../test_pub.dart';
-
-main() {
-  initConfig();
-  integration("includes source map URLs in a debug build", () {
-    d.dir(appPath, [
-      d.appPubspec(),
-      d.dir("web", [
-        d.file("main.dart", "void main() => print('hello');")
-      ])
-    ]).create();
-
-    schedulePub(args: ["build", "--mode", "debug"],
-        output: new RegExp(r'Built \d+ files to "build".'),
-        exitCode: 0);
-
-    d.dir(appPath, [
-      d.dir('build', [
-        d.dir('web', [
-          d.matcherFile('main.dart.js',
-              contains("# sourceMappingURL=main.dart.js.map")),
-          d.matcherFile('main.dart.js.map', contains('"file": "main.dart.js"'))
-        ])
-      ])
-    ]).validate();
-  });
-}