Remove generated directories with 100s of files.

client/dom/generated/src/wrapping/_HTMLDetailsElementWrappingImplementation.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 _HTMLDetailsElementWrappingImplementation extends _HTMLElementWrappingImplementation implements HTMLDetailsElement {
-  _HTMLDetailsElementWrappingImplementation() : super() {}
-
-  static create__HTMLDetailsElementWrappingImplementation() native {
-    return new _HTMLDetailsElementWrappingImplementation();
-  }
-
-  bool get open() { return _get_open(this); }
-  static bool _get_open(var _this) native;
-
-  void set open(bool value) { _set_open(this, value); }
-  static void _set_open(var _this, bool value) native;
-
-  String get typeName() { return "HTMLDetailsElement"; }
-}