Generate dummy dom to replace wrapping dom for dartc.

client/dom/src/wrapping_GlobalProperties.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.
+
+Window get window() {
+  return _NativeDomGlobalProperties.getWindow();
+}
+
+// TODO(vsm): Remove when prefixes are supported.
+Window get dom_window() {
+  return _NativeDomGlobalProperties.getWindow();
+}
+
+Document get document() {
+  return _NativeDomGlobalProperties.getDocument();
+}
+
+class _NativeDomGlobalProperties {
+  static Window getWindow() native;
+  static Document getDocument() native;
+}