Remove generated directories with 100s of files.

client/dom/generated/src/wrapping/_DOMPluginWrappingImplementation.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 _DOMPluginWrappingImplementation extends DOMWrapperBase implements DOMPlugin {
-  _DOMPluginWrappingImplementation() : super() {}
-
-  static create__DOMPluginWrappingImplementation() native {
-    return new _DOMPluginWrappingImplementation();
-  }
-
-  String get description() { return _get_description(this); }
-  static String _get_description(var _this) native;
-
-  String get filename() { return _get_filename(this); }
-  static String _get_filename(var _this) native;
-
-  int get length() { return _get_length(this); }
-  static int _get_length(var _this) native;
-
-  String get name() { return _get_name(this); }
-  static String _get_name(var _this) native;
-
-  DOMMimeType item(int index) {
-    return _item(this, index);
-  }
-  static DOMMimeType _item(receiver, index) native;
-
-  DOMMimeType namedItem(String name) {
-    return _namedItem(this, name);
-  }
-  static DOMMimeType _namedItem(receiver, name) native;
-
-  String get typeName() { return "DOMPlugin"; }
-}