Remove generated directories with 100s of files.

client/dom/generated/src/wrapping/_ElementTraversalWrappingImplementation.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 _ElementTraversalWrappingImplementation extends DOMWrapperBase implements ElementTraversal {
-  _ElementTraversalWrappingImplementation() : super() {}
-
-  static create__ElementTraversalWrappingImplementation() native {
-    return new _ElementTraversalWrappingImplementation();
-  }
-
-  int get childElementCount() { return _get_childElementCount(this); }
-  static int _get_childElementCount(var _this) native;
-
-  Element get firstElementChild() { return _get_firstElementChild(this); }
-  static Element _get_firstElementChild(var _this) native;
-
-  Element get lastElementChild() { return _get_lastElementChild(this); }
-  static Element _get_lastElementChild(var _this) native;
-
-  Element get nextElementSibling() { return _get_nextElementSibling(this); }
-  static Element _get_nextElementSibling(var _this) native;
-
-  Element get previousElementSibling() { return _get_previousElementSibling(this); }
-  static Element _get_previousElementSibling(var _this) native;
-
-  String get typeName() { return "ElementTraversal"; }
-}