NS_WITH_SERVICE(nsIPref, prefs, NS_PREF_CONTRACTID, &rv); if (NS_SUCCEEDED(rv)) {  prefs->GetBoolPref(kDisableXULCachePref, &gDisableXULCache); prefs->RegisterCallback(kDisableXULCachePref, DisableXULCacheChangedCallback, nsnull); }
NS_NewXULPrototypeCache(nsISupports* aOuter, REFNSIID aIID, void** aResult){    NS_PRECONDITION(! aOuter, "no aggregation");    if (aOuter)        return NS_ERROR_NO_AGGREGATION;    nsXULPrototypeCache* result = new nsXULPrototypeCache();    if (! result)        return NS_ERROR_OUT_OF_MEMORY;    nsresult rv;    NS_ADDREF(result);    rv = result->QueryInterface(aIID, aResult);    NS_RELEASE(result);    return rv;}