Remove generated directories with 100s of files.

client/dom/generated/src/wrapping/_WebKitAnimationEventWrappingImplementation.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 _WebKitAnimationEventWrappingImplementation extends _EventWrappingImplementation implements WebKitAnimationEvent {
-  _WebKitAnimationEventWrappingImplementation() : super() {}
-
-  static create__WebKitAnimationEventWrappingImplementation() native {
-    return new _WebKitAnimationEventWrappingImplementation();
-  }
-
-  String get animationName() { return _get_animationName(this); }
-  static String _get_animationName(var _this) native;
-
-  num get elapsedTime() { return _get_elapsedTime(this); }
-  static num _get_elapsedTime(var _this) native;
-
-  String get typeName() { return "WebKitAnimationEvent"; }
-}