Remove generated directories with 100s of files.

client/dom/generated/src/wrapping/_BlobWrappingImplementation.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 _BlobWrappingImplementation extends DOMWrapperBase implements Blob {
-  _BlobWrappingImplementation() : super() {}
-
-  static create__BlobWrappingImplementation() native {
-    return new _BlobWrappingImplementation();
-  }
-
-  int get size() { return _get_size(this); }
-  static int _get_size(var _this) native;
-
-  String get type() { return _get_type(this); }
-  static String _get_type(var _this) native;
-
-  Blob webkitSlice([int start = null, int end = null, String contentType = null]) {
-    if (start === null) {
-      if (end === null) {
-        if (contentType === null) {
-          return _webkitSlice(this);
-        }
-      }
-    } else {
-      if (end === null) {
-        if (contentType === null) {
-          return _webkitSlice_2(this, start);
-        }
-      } else {
-        if (contentType === null) {
-          return _webkitSlice_3(this, start, end);
-        } else {
-          return _webkitSlice_4(this, start, end, contentType);
-        }
-      }
-    }
-    throw "Incorrect number or type of arguments";
-  }
-  static Blob _webkitSlice(receiver) native;
-  static Blob _webkitSlice_2(receiver, start) native;
-  static Blob _webkitSlice_3(receiver, start, end) native;
-  static Blob _webkitSlice_4(receiver, start, end, contentType) native;
-
-  String get typeName() { return "Blob"; }
-}