Remove generated directories with 100s of files.

client/dom/generated/src/wrapping/_HTMLSourceElementWrappingImplementation.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 _HTMLSourceElementWrappingImplementation extends _HTMLElementWrappingImplementation implements HTMLSourceElement {
-  _HTMLSourceElementWrappingImplementation() : super() {}
-
-  static create__HTMLSourceElementWrappingImplementation() native {
-    return new _HTMLSourceElementWrappingImplementation();
-  }
-
-  String get media() { return _get_media(this); }
-  static String _get_media(var _this) native;
-
-  void set media(String value) { _set_media(this, value); }
-  static void _set_media(var _this, String value) native;
-
-  String get src() { return _get_src(this); }
-  static String _get_src(var _this) native;
-
-  void set src(String value) { _set_src(this, value); }
-  static void _set_src(var _this, String value) native;
-
-  String get type() { return _get_type(this); }
-  static String _get_type(var _this) native;
-
-  void set type(String value) { _set_type(this, value); }
-  static void _set_type(var _this, String value) native;
-
-  String get typeName() { return "HTMLSourceElement"; }
-}