Move pub into sdk/lib/_internal.

utils/tests/pub/install/hosted/cached_pubspec_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 'package:pathos/path.dart' as path;
-import 'package:scheduled_test/scheduled_test.dart';
-
-import '../../../../pub/io.dart';
-import '../../descriptor.dart' as d;
-import '../../test_pub.dart';
-
-main() {
-  initConfig();
-
-  integration('does not request a pubspec for a cached package', () {
-    servePackages([packageMap("foo", "1.2.3")]);
-
-    d.appDir([dependencyMap("foo", "1.2.3")]).create();
-
-    // Run install once so it gets cached.
-    schedulePub(args: ['install'],
-        output: new RegExp("Dependencies installed!\$"));
-
-    // Clear the cache. We don't care about anything that was served during
-    // the initial install.
-    getRequestedPaths();
-
-    d.cacheDir({"foo": "1.2.3"}).validate();
-    d.packagesDir({"foo": "1.2.3"}).validate();
-
-    // Run the solver again now that it's cached.
-    schedulePub(args: ['install'],
-        output: new RegExp("Dependencies installed!\$"));
-
-    // The update should not have requested the pubspec since it's installed
-    // locally already.
-    getRequestedPaths().then((paths) {
-      expect(paths, isNot(contains("packages/foo/versions/1.2.3.yaml")));
-    });
-  });
-}