anchor.diff:  
   part of dart.io;
   
  -class _Timer implements Timer {
  -  // Set jitter to wake up timer events that would happen in _TIMER_JITTER ms.
  -  static const int _TIMER_JITTER = 0;
  -
  +class _Timer extends LinkedListEntry<_Timer> implements Timer {
     // Disables the timer.
     static const int _NO_TIMER = -1;
   
  +  // Timers are ordered by wakeup time.
  +  static LinkedList<_Timer> _timers = new LinkedList<_Timer>();
  +
  +  static ReceivePort _receivePort;
  +  static bool _handling_callbacks = false;
  +
  +  Function _callback;
  +  int _milliSeconds;
  +  int _wakeupTime;
  +
     static Timer _createTimer(void callback(Timer timer),
  -                           int milliSeconds,
  -                           bool repeating) {
  +                            int milliSeconds,
  +                            bool repeating) {
       _EventHandler._start();
  -    if (_timers == null) {
  -      _timers = new DoubleLinkedQueue<_Timer>();
  -    }
       _Timer timer = new _Timer._internal();
       timer._callback = callback;
  -    timer._milliSeconds = milliSeconds;
  -    timer._wakeupTime = (new DateTime.now()).millisecondsSinceEpoch + milliSeconds;
  -    timer._repeating = repeating;
  +    timer._wakeupTime =
  +        new DateTime.now().millisecondsSinceEpoch + milliSeconds;
  +    timer._milliSeconds = repeating ? milliSeconds : -1;
       timer._addTimerToList();
       timer._notifyEventHandler();
       return timer;
  
positive.code:       return;
      }
  
      if (_timers.firstEntry() == null) {
        // No pending timers: Close the receive port and let the event handler
        // know.
        if (_receivePort != null) {
  
negative.code:       }
        _EventHandler._sendData(null,
                                _receivePort,
                                _timers.first._wakeupTime);
      }
    }
  
  