Update Timer API to take the callback as the last parameter.

client/testing/unittest/unittest_vm.dart

Index: client/testing/unittest/unittest_vm.dart
diff --git a/client/testing/unittest/unittest_vm.dart b/client/testing/unittest/unittest_vm.dart
index 0035b79be7c029ae98d633c36a259f087f895fa9..b3219398f503fdbcb647559f332d3e92087d4a5a 100644
--- a/client/testing/unittest/unittest_vm.dart
+++ b/client/testing/unittest/unittest_vm.dart
@@ -1,4 +1,4 @@
-// Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
+// Copyright (c) 2012, 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.
 
@@ -15,9 +15,9 @@ _platformInitialize() {
 }
 
 _platformDefer(void callback()) {
-  new Timer((timer) {
+  new Timer(0, (timer) {
     callback();
-  }, 0);
+  });
 }
 
 _platformStartTests() {