Move pub into sdk/lib/_internal.

utils/pub/validator/license.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 pubspec_field_validator;
-
-import 'dart:async';
-
-import 'package:pathos/path.dart' as path;
-
-import '../entrypoint.dart';
-import '../io.dart';
-import '../system_cache.dart';
-import '../validator.dart';
-
-/// A validator that checks that a LICENSE-like file exists.
-class LicenseValidator extends Validator {
-  LicenseValidator(Entrypoint entrypoint)
-    : super(entrypoint);
-
-  Future validate() {
-    return new Future.sync(() {
-      var licenseLike = new RegExp(
-          r"^([a-zA-Z0-9]+[-_])?(LICENSE|COPYING)(\..*)?$");
-      if (listDir(entrypoint.root.dir)
-          .map(path.basename)
-          .any(licenseLike.hasMatch)) {
-        return;
-      }
-
-      errors.add(
-          "You must have a COPYING or LICENSE file in the root directory.\n"
-          "An open-source license helps ensure people can legally use your "
-          "code.");
-    });
-  }
-}