Remove generated directories with 100s of files.

client/dom/generated/src/wrapping/_CSSMediaRuleWrappingImplementation.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 _CSSMediaRuleWrappingImplementation extends _CSSRuleWrappingImplementation implements CSSMediaRule {
-  _CSSMediaRuleWrappingImplementation() : super() {}
-
-  static create__CSSMediaRuleWrappingImplementation() native {
-    return new _CSSMediaRuleWrappingImplementation();
-  }
-
-  CSSRuleList get cssRules() { return _get_cssRules(this); }
-  static CSSRuleList _get_cssRules(var _this) native;
-
-  MediaList get media() { return _get_media(this); }
-  static MediaList _get_media(var _this) native;
-
-  void deleteRule(int index) {
-    _deleteRule(this, index);
-    return;
-  }
-  static void _deleteRule(receiver, index) native;
-
-  int insertRule(String rule, int index) {
-    return _insertRule(this, rule, index);
-  }
-  static int _insertRule(receiver, rule, index) native;
-
-  String get typeName() { return "CSSMediaRule"; }
-}