rem: if (aDragDropObserver.onDragExit) 
add: if ("onDragExit" in aDragDropObserver) 
context:   dragExit: function (aEvent, aDragDropObserver)    {      if (aDragDropObserver.onDragExit)        aDragDropObserver.onDragExit(aEvent, this.mDragSession);    },  
meta: 5872	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/5872/910b9ea5006fff5af4d16b76be841a0594578c74/nsDragAndDrop.js/clean/xpfe/global/resources/content/nsDragAndDrop.js