Rework Timer interface.

tests/standalone/io/http_auth_test.dart

 // 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.
 
 import 'dart:async';
 import 'dart:crypto';
 import 'dart:io';
 import 'dart:isolate';
 import 'dart:uri';
 import 'dart:utf';
@@ skipping 150 matching lines @@
   HttpClient client = new HttpClient();
   bool passwordChanged = false;
 
   client.authenticate = (Uri url, String scheme, String realm) {
     Expect.equals("Basic", scheme);
     Expect.equals("realm", realm);
     String username = url.path.substring(1, 6);
     String password = url.path.substring(1, 6);
     if (passwordChanged) password = "${password}1";
     Completer completer = new Completer();
-    new Timer(10, (_) {
+    new Timer(const Duration(milliseconds: 10), () {
       client.addCredentials(
           url, realm, new HttpClientBasicCredentials(username, password));
       completer.complete(true);
     });
     return completer.future;
   };
 
   Future makeRequest(Uri url) {
     Completer completer = new Completer();
     HttpClientConnection conn = client.getUrl(url);
@@ skipping 80 matching lines @@
 main() {
   testUrlUserInfo();
   testBasicNoCredentials();
   testBasicCredentials();
   testBasicAuthenticateCallback();
   // These teste are not normally run. They can be used for locally
   // testing with another web server (e.g. Apache).
   //testLocalServerBasic();
   //testLocalServerDigest();
 }