Remove generated directories with 100s of files.

client/dom/generated/src/wrapping/_CSSValueWrappingImplementation.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 _CSSValueWrappingImplementation extends DOMWrapperBase implements CSSValue {
-  _CSSValueWrappingImplementation() : super() {}
-
-  static create__CSSValueWrappingImplementation() native {
-    return new _CSSValueWrappingImplementation();
-  }
-
-  String get cssText() { return _get_cssText(this); }
-  static String _get_cssText(var _this) native;
-
-  void set cssText(String value) { _set_cssText(this, value); }
-  static void _set_cssText(var _this, String value) native;
-
-  int get cssValueType() { return _get_cssValueType(this); }
-  static int _get_cssValueType(var _this) native;
-
-  String get typeName() { return "CSSValue"; }
-}