Remove generated directories with 100s of files.

client/dom/generated/src/wrapping/_ShadowRootWrappingImplementation.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 _ShadowRootWrappingImplementation extends _DocumentFragmentWrappingImplementation implements ShadowRoot {
-  _ShadowRootWrappingImplementation() : super() {}
-
-  static create__ShadowRootWrappingImplementation() native {
-    return new _ShadowRootWrappingImplementation();
-  }
-
-  Element get host() { return _get_host(this); }
-  static Element _get_host(var _this) native;
-
-  String get innerHTML() { return _get_innerHTML(this); }
-  static String _get_innerHTML(var _this) native;
-
-  void set innerHTML(String value) { _set_innerHTML(this, value); }
-  static void _set_innerHTML(var _this, String value) native;
-
-  Element getElementById(String elementId) {
-    return _getElementById(this, elementId);
-  }
-  static Element _getElementById(receiver, elementId) native;
-
-  NodeList getElementsByClassName(String className) {
-    return _getElementsByClassName(this, className);
-  }
-  static NodeList _getElementsByClassName(receiver, className) native;
-
-  NodeList getElementsByTagName(String tagName) {
-    return _getElementsByTagName(this, tagName);
-  }
-  static NodeList _getElementsByTagName(receiver, tagName) native;
-
-  NodeList getElementsByTagNameNS(String namespaceURI, String localName) {
-    return _getElementsByTagNameNS(this, namespaceURI, localName);
-  }
-  static NodeList _getElementsByTagNameNS(receiver, namespaceURI, localName) native;
-
-  String get typeName() { return "ShadowRoot"; }
-}