Remove generated directories with 100s of files.

client/dom/generated/src/wrapping/_DeviceMotionEventWrappingImplementation.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 _DeviceMotionEventWrappingImplementation extends _EventWrappingImplementation implements DeviceMotionEvent {
-  _DeviceMotionEventWrappingImplementation() : super() {}
-
-  static create__DeviceMotionEventWrappingImplementation() native {
-    return new _DeviceMotionEventWrappingImplementation();
-  }
-
-  num get interval() { return _get_interval(this); }
-  static num _get_interval(var _this) native;
-
-  String get typeName() { return "DeviceMotionEvent"; }
-}