Rework Timer interface.

tests/standalone/io/http_shutdown_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:io";
 
 void test1(int totalConnections) {
   // Server which just closes immediately.
@@ skipping 98 matching lines @@
     };
   }
 }
 
 
 void test4() {
   var server = new HttpServer();
   server.listen("127.0.0.1", 0);
   server.defaultRequestHandler = (var request, var response) {
     request.inputStream.onClosed = () {
-      new Timer.repeating(100, (timer) {
+      new Timer.repeating(new Duration(milliseconds: 100), (timer) {
         if (server.connectionsInfo().total == 0) {
           server.close();
           timer.cancel();
         }
       });
       response.outputStream.close();
     };
   };
 
   var client= new HttpClient();
@@ skipping 20 matching lines @@
   // Create a number of client requests and keep then active. Then
   // close the client and wait for the server to lose all active
   // connections.
   var client= new HttpClient();
   for (int i = 0; i < totalConnections; i++) {
     var conn = client.post("127.0.0.1", server.port, "/");
     conn.onRequest = (req) { req.outputStream.write([0]); };
     conn.onError = (e) => Expect.isTrue(e is HttpException);
   }
   bool clientClosed = false;
-  new Timer.repeating(100, (timer) {
+  new Timer.repeating(new Duration(milliseconds: 100), (timer) {
     if (!clientClosed) {
       if (server.connectionsInfo().total == totalConnections) {
         clientClosed = true;
         client.shutdown(force: true);
       }
     } else {
       if (server.connectionsInfo().total == 0) {
         server.close();
         timer.cancel();
       }
     }
   });
 }
 
 
 void main() {
   test1(1);
   test1(10);
   test2(1, 10);
   test2(10, 10);
   test2(10, 1000);
   test3(1);
   test3(10);
   test4();
   test5(1);
   test5(10);
 }