      * 
      *  The scrollbars are made visible if the viewport's content size is
      *  bigger than the actual size.
-     * 
-     *  If the visibility of either scrollbar changes we apply invalidateSize()
-     *  to the ScrollerSkin.
-     * 
-     *  This causes new values for measuredWidth,Height to be computed, and 
-     *  it causes the update process to be restarted.
-     * 
-     *  Note also: the logic for calling updateDisplayList and then restarting
-     *  the process if the component has become invalid is in
-     *  mx.managers.LayoutManager::validateDisplayList.
-     * 
      */
     override public function updateDisplayList(w:Number, h:Number):void
     {  

                if (vsb) showVSB = true; 
                break;
            case ScrollPolicy.AUTO: 
                if (vsb) showVSB = vsb.visible; 
                break;
        }
        
        var measuredW:Number = 0;
        var measuredH:Number = 0;
        var minW:Number = 0;
        var minH:Number = 0;            
        
        var viewport:IViewport = scroller.viewport;
        if (viewport)
        {
            var viewportElt:ILayoutElement = LayoutElementFor(viewport);
            measuredW = viewportElt.getPreferredBoundsWidth();
            measuredH = viewportElt.getPreferredBoundsHeight();
        }
        
        if (showHSB)

import mx.components.baseClasses.GroupBase;
import mx.components.Skin;

[ExcludeClass]

/**
 *  @private
 */
internal class FxScrollerLayout extends LayoutBase
{
    public function FxScrollerLayout()    
