rem: return aElem.ownerDocument .defaultView .getComputedStyle(aElem, "").getPropertyValue(aProp); 
add: return elem.ownerDocument .defaultView .getComputedStyle(aElem, "").getPropertyValue(prop); 
context:   getComputedStyle: function(aElem, aProp) {    return aElem.ownerDocument                .defaultView                .getComputedStyle(aElem, "").getPropertyValue(aProp);  },
meta: 8395	/local1/tlutelli/issta_data/temp/all_js/javascript/2007_temp/2007/8395/67d4cd30c1b8a39f8922a8bd66651bee5a1aa065/nsContextMenu.js/buggy/browser/base/content/nsContextMenu.js