Reapply remove setTimeout, take 3.

samples/swarm/swarm_ui_lib/touch/Scrollbar.dart

 // Copyright (c) 2011, 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 touch;
 
 /**
  * Implementation of a scrollbar for the custom scrolling behavior
  * defined in [:Scroller:].
  */
@@ skipping 34 matching lines @@
    */
   Function _boundHideFn;
 
   Element _verticalElement;
   Element _horizontalElement;
 
   int _currentScrollStartMouse;
   num _currentScrollStartOffset;
   bool _currentScrollVertical;
   num _currentScrollRatio;
-  num _timerId;
+  Timer _timer;
 
   bool _displayOnHover;
   bool _hovering = false;
 
   Scrollbar(Scroller scroller, [displayOnHover = true]) :
       _displayOnHover = displayOnHover,
       _scroller = scroller,
       _frame = scroller.getFrame(),
       _cachedSize = new Map<String, num>() {
     _boundHideFn = () { _showScrollbars(false); };
@@ skipping 75 matching lines @@
             _cancelTimeout();
             _showScrollbars(true);
             refresh();
           }
         });
       _frame.onMouseOut.listen((e) {
           _hovering = false;
           // Start hiding immediately if we aren't
           // scrolling or already in the process of
           // hidng the scrollbar
-          if (!_scrollInProgress && _timerId == null) {
+          if (!_scrollInProgress && _timer == null) {
             _boundHideFn();
           }
         });
     }
   }
 
   void _onStart(UIEvent e) {
     Element elementOver = e.target;
     if (elementOver == _verticalElement ||
         elementOver == _horizontalElement) {
@@ skipping 63 matching lines @@
     _scroller._onScrollerDragEnd.add(
         new Event(ScrollerEventType.DRAG_END));
   }
 
 
   /**
    * When scrolling ends, schedule a timeout to hide the scrollbars.
    */
   void _onScrollerEnd(Event e) {
     _cancelTimeout();
-    _timerId = window.setTimeout(_boundHideFn, _DISPLAY_TIME);
+    _timer = new Timer(const Duration(milliseconds: _DISPLAY_TIME),
+        _boundHideFn);
     _scrollInProgress = false;
   }
   void onScrollerMoved(num scrollX, num scrollY, bool decelerating) {
     if (_scrollInProgress == false) {
       // Display the scrollbar and then immediately prepare to hide it...
       _onScrollerStart(null);
       _onScrollerEnd(null);
     }
     updateScrollbars(scrollX, scrollY);
   }
@@ skipping 28 matching lines @@
   /**
    * When scrolling starts, show scrollbars and clear hide intervals.
    */
   void _onScrollerStart(Event e) {
     _scrollInProgress = true;
     _cancelTimeout();
     _showScrollbars(true);
   }
 
   void _cancelTimeout() {
-    if (_timerId != null) {
-      window.clearTimeout(_timerId);
-      _timerId = null;
+    if (_timer != null) {
+      _timer.cancel();
+      _timer = null;
     }
   }
 
   /**
    * Show or hide the scrollbars by changing the opacity.
    */
   void _showScrollbars(bool show) {
     if (_hovering == true && _displayOnHover) {
       show = true;
     }
@@ skipping 48 matching lines @@
     style.setProperty(cssPos, '${pos}px', '');
     if (_cachedSize[cssSize] != size) {
       _cachedSize[cssSize] = size;
       style.setProperty(cssSize, '${size}px', '');
     }
     if (element.parent == null) {
       _frame.nodes.add(element);
     }
   }
 }