Remove generated directories with 100s of files.

client/dom/generated/src/wrapping/_OverflowEventWrappingImplementation.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 _OverflowEventWrappingImplementation extends _EventWrappingImplementation implements OverflowEvent {
-  _OverflowEventWrappingImplementation() : super() {}
-
-  static create__OverflowEventWrappingImplementation() native {
-    return new _OverflowEventWrappingImplementation();
-  }
-
-  bool get horizontalOverflow() { return _get_horizontalOverflow(this); }
-  static bool _get_horizontalOverflow(var _this) native;
-
-  int get orient() { return _get_orient(this); }
-  static int _get_orient(var _this) native;
-
-  bool get verticalOverflow() { return _get_verticalOverflow(this); }
-  static bool _get_verticalOverflow(var _this) native;
-
-  String get typeName() { return "OverflowEvent"; }
-}