Rework Timer interface.

tests/html/dromaeo_smoke_test.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.
 
 library dromaeo;
 import '../../pkg/unittest/lib/unittest.dart';
 import '../../pkg/unittest/lib/html_config.dart';
 import '../../samples/third_party/dromaeo/Dromaeo.dart' as originalTest;
 import 'dart:html';
 import 'dart:async';
@@ skipping 27 matching lines @@
     </div>
     <ul id="tests">
       <li><a href="?dom">Smoke Tests</a></li>
     </ul>
   </div>''';
 
   bool isDone = false;
   originalTest.main();
 
   test('dromaeo runs', () {
-    new Timer.repeating(500, expectAsyncUntil1((timer) {
+    new Timer.repeating(new Duration(milliseconds: 500),
+                        expectAsyncUntil1((timer) {
       if (document.query('.alldone') != null) {
         timer.cancel();
         isDone = true;
       }
     }, () => isDone));
   });
 }