rem: var catMgr = Components.classes["@mozilla.org/categorymanager;1"] .getService(Components.interfaces.nsICategoryManager); var entry = catMgr.getCategoryEntry("Gecko-Content-Viewers", contentType); if (entry) { return true; }  return false; 
add: var webNavInfo = Components.classes["@mozilla.org/webnavigation-info;1"] .getService(Components.interfaces.nsIWebNavigationInfo); return webNavInfo.isTypeSupported(contentType, null); 
context:     isPreferred: function(contentType, desiredContentType)    {        try {            var catMgr = Components.classes["@mozilla.org/categorymanager;1"]                        .getService(Components.interfaces.nsICategoryManager);            var entry = catMgr.getCategoryEntry("Gecko-Content-Viewers",                                                contentType);            if (entry) {                return true;            }            return false;        } catch (e) {            // XXX propagate failures other than "NS_ERROR_NOT_AVAILABLE"?            // This seems to never get called, so not like it matters....            return false;        }    },
meta: 8395	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/8395/8efc76dc9a2f8a5c7a6d620258004c269af07078/nsBrowserContentListener.js/clean/xpfe/browser/resources/content/nsBrowserContentListener.js