Rework Timer interface.

sdk/lib/io/http_session.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.
 
 part of dart.io;
 
 const String _DART_SESSION_ID = "DARTSESSID";
 
 // A _HttpSession is a node in a double-linked list, with _next and _prev being
 // the previous and next pointers.
@@ skipping 107 matching lines @@
       _head = session._next;
       _stopTimer();
       _startTimer();
     }
     if (_tail == session) {
       _tail = session._prev;
     }
     session._next = session._prev = null;
   }
 
-  void _timerTimeout(_) {
+  void _timerTimeout() {
     _stopTimer();  // Clear timer.
     assert(_head != null);
     var session = _head;
     session.destroy();  // Will remove the session from timeout queue and map.
     if (session._timeoutCallback != null) {
       session._timeoutCallback();
     }
   }
 
   void _startTimer() {
     assert(_timer == null);
     if (_head != null) {
       int seconds = new DateTime.now().difference(_head.lastSeen).inSeconds;
-      _timer = new Timer((_sessionTimeout - seconds) * 1000, _timerTimeout);
+      _timer = new Timer(new Duration(seconds: _sessionTimeout - seconds),
+                         _timerTimeout);
     }
   }
 
   void _stopTimer() {
     if (_timer != null) {
       _timer.cancel();
       _timer = null;
     }
   }
 
   Map<String, _HttpSession> _sessions;
   int _sessionTimeout = 20 * 60;  // 20 mins.
   _HttpSession _head;
   _HttpSession _tail;
   Timer _timer;
 
   external static Uint8List _getRandomBytes(int count);
 }