     //
     //--------------------------------------------------------------------------
 
-    /**
-     *  The size of the track, which equals the height of the track.
-     *  
-     *  @langversion 3.0
-     *  @playerversion Flash 10
-     *  @playerversion AIR 1.5
-     *  @productversion Flex 4
-     */
-    override protected function get trackSize():Number
-    {
-        if (track)
-            return track.height;
-        else
-            return 0;
-    }
-    
     override public function set viewport(newViewport:IViewport):void
     {
         super.viewport = newViewport;

     *
     *  <p>If <code>viewport</code> is null, 
     *  change the vertical scroll position for line up or line down by calling 
     *  the <code>step()</code> method.</p>
     *
     *  @param increase Whether the line scoll is up (<code>true</code>) or
     *  down (<code>false</code>). 
     * 
     *  @see mx.components.baseClasses.TrackBase#step()
     *  @see mx.components.baseClasses.TrackBase#setValue()
     *  @see spark.core.IViewport
     *  @see spark.core.IViewport#verticalScrollPosition

            stepSize = Math.abs(viewport.getVerticalScrollPositionDelta(
                (increase) ? NavigationUnit.DOWN : NavigationUnit.UP));
        }
        super.changeValueByStep(increase);
        if (viewport)
            stepSize = oldStepSize;
    } 
