Change core lib, dart2js, and more for new optional parameters syntax

utils/pub/source.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 source;
 
 import 'io.dart';
 import 'package.dart';
 import 'pubspec.dart';
 import 'system_cache.dart';
@@ skipping 136 matching lines @@
    * When a [Pubspec] or [LockFile] is parsed, it reads in the description for
    * each dependency. It is up to the dependency's [Source] to determine how
    * that should be interpreted. This will be called during parsing to validate
    * that the given [description] is well-formed according to this source. It
    * should return if the description is valid, or throw a [FormatException] if
    * not.
    *
    * [fromLockFile] is true when the description comes from a [LockFile], to
    * allow the source to use lockfile-specific descriptions via [resolveId].
    */
-  void validateDescription(description, [bool fromLockFile=false]) {}
+  void validateDescription(description, {bool fromLockFile: false}) {}
 
   /**
    * Returns whether or not [description1] describes the same package as
    * [description2] for this source. This method should be light-weight. It
    * doesn't need to validate that either package exists.
    *
    * By default, this assumes both descriptions are strings and compares them
    * for equality.
    */
   bool descriptionsEqual(description1, description2) =>
@@ skipping 15 matching lines @@
    *
    * The returned [PackageId] may have a description field that's invalid
    * according to [validateDescription], although it must still be serializable
    * to JSON and YAML. It must also be equal to [id] according to
    * [descriptionsEqual].
    *
    * By default, this just returns [id].
    */
   Future<PackageId> resolveId(PackageId id) => new Future.immediate(id);
 }