Start pulling pub from its own repo.

sdk/lib/_internal/pub/test/build/copies_non_dart_files_to_build_test.dart

-// Copyright (c) 2013, 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 '../descriptor.dart' as d;
-import '../test_pub.dart';
-
-main() {
-  initConfig();
-
-  integration("copies non-Dart files to build/", () {
-    servePackages((builder) => builder.serve("browser", "1.0.0"));
-
-    d.dir(appPath, [
-      // A browser dependency with no entrypoints shouldn't cause dart.js to be
-      // copied in.
-      d.appPubspec({"browser": "1.0.0"}),
-      d.dir('web', [
-        d.file('file.txt', 'contents'),
-        d.dir('subdir', [
-          d.file('subfile.txt', 'subcontents')
-        ])
-      ])
-    ]).create();
-
-    schedulePub(args: ["build"],
-        output: new RegExp(r'Built 2 files to "build".'));
-
-    d.dir(appPath, [
-      d.dir('build', [
-        d.dir('web', [
-          d.nothing('packages'),
-          d.file('file.txt', 'contents'),
-          d.dir('subdir', [
-            d.file('subfile.txt', 'subcontents')
-          ])
-        ])
-      ])
-    ]).validate();
-  });
-}