pkg/unittest: Run tests in zones

tools/dom/src/shared_html.dart

 // Copyright (c) 2013, 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.
 
 part of dart.dom.html;
 
-_wrapZone(callback) {
+_wrapZone(callback(arg)) {
   // For performance reasons avoid wrapping if we are in the root zone.
   if (Zone.current == Zone.ROOT) return callback;
+  if (callback == null) return null;
   return Zone.current.bindUnaryCallback(callback, runGuarded: true);
 }
 
-_wrapBinaryZone(callback) {
+_wrapBinaryZone(callback(arg1, arg2)) {
   if (Zone.current == Zone.ROOT) return callback;
+  if (callback == null) return null;
   return Zone.current.bindBinaryCallback(callback, runGuarded: true);
 }
 
 /**
  * Alias for [querySelector]. Note this function is deprecated because its
  * semantics will be changing in the future.
  */
 @deprecated
 @Experimental()
 Element query(String relativeSelectors) => document.query(relativeSelectors);
@@ skipping 34 matching lines @@
  * save typing a few characters.
  *
  * [selectors] should be a string using CSS selector syntax.
  *
  *     var items = document.querySelectorAll('.itemClassName');
  *
  * For details about CSS selector syntax, see the
  * [CSS selector specification](http://www.w3.org/TR/css3-selectors/).
  */
 ElementList querySelectorAll(String selectors) => document.querySelectorAll(selectors);