Remove generated directories with 100s of files.

client/dom/generated/src/wrapping/_FileWrappingImplementation.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 _FileWrappingImplementation extends _BlobWrappingImplementation implements File {
-  _FileWrappingImplementation() : super() {}
-
-  static create__FileWrappingImplementation() native {
-    return new _FileWrappingImplementation();
-  }
-
-  String get fileName() { return _get_fileName(this); }
-  static String _get_fileName(var _this) native;
-
-  int get fileSize() { return _get_fileSize(this); }
-  static int _get_fileSize(var _this) native;
-
-  Date get lastModifiedDate() { return _get_lastModifiedDate(this); }
-  static Date _get_lastModifiedDate(var _this) native;
-
-  String get name() { return _get_name(this); }
-  static String _get_name(var _this) native;
-
-  String get webkitRelativePath() { return _get_webkitRelativePath(this); }
-  static String _get_webkitRelativePath(var _this) native;
-
-  String get typeName() { return "File"; }
-}