Support DOMString[] and regenerate from IDL

client/dom/generated/src/wrapping/_DataTransferItemsWrappingImplementation.dart

-// Copyright (c) 2011, 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.
-
-// WARNING: Do not edit - generated code.
-
-class _DataTransferItemsWrappingImplementation extends DOMWrapperBase implements DataTransferItems {
-  _DataTransferItemsWrappingImplementation() : super() {}
-
-  static create__DataTransferItemsWrappingImplementation() native {
-    return new _DataTransferItemsWrappingImplementation();
-  }
-
-  int get length() { return _get__DataTransferItems_length(this); }
-  static int _get__DataTransferItems_length(var _this) native;
-
-  void add(String data, String type) {
-    _add(this, data, type);
-    return;
-  }
-  static void _add(receiver, data, type) native;
-
-  void clear() {
-    _clear(this);
-    return;
-  }
-  static void _clear(receiver) native;
-
-  DataTransferItem item(int index) {
-    return _item(this, index);
-  }
-  static DataTransferItem _item(receiver, index) native;
-
-  String get typeName() { return "DataTransferItems"; }
-}