Mark VoidCallback as a [Callback]

client/dom/generated/src/wrapping/_VoidCallbackWrappingImplementation.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 _VoidCallbackWrappingImplementation extends DOMWrapperBase implements VoidCallback {
-  _VoidCallbackWrappingImplementation() : super() {}
-
-  static create__VoidCallbackWrappingImplementation() native {
-    return new _VoidCallbackWrappingImplementation();
-  }
-
-  void handleEvent() {
-    _handleEvent(this);
-    return;
-  }
-  static void _handleEvent(receiver) native;
-
-  String get typeName() { return "VoidCallback"; }
-}