Support 'Conditional' idl attribute.

client/dom/generated/src/wrapping/_HTMLPropertiesCollectionWrappingImplementation.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 _HTMLPropertiesCollectionWrappingImplementation extends _HTMLCollectionWrappingImplementation implements HTMLPropertiesCollection {
-  _HTMLPropertiesCollectionWrappingImplementation() : super() {}
-
-  static create__HTMLPropertiesCollectionWrappingImplementation() native {
-    return new _HTMLPropertiesCollectionWrappingImplementation();
-  }
-
-  int get length() { return _get_length_HTMLPropertiesCollection(this); }
-  static int _get_length_HTMLPropertiesCollection(var _this) native;
-
-  Node item(int index) {
-    return _item_HTMLPropertiesCollection(this, index);
-  }
-  static Node _item_HTMLPropertiesCollection(receiver, index) native;
-
-  String get typeName() { return "HTMLPropertiesCollection"; }
-}