nsresult rv;  nsCOMPtr<nsIPrefBranch> prefBranch = do_QueryInterface(mPrefService, &rv); if (NS_FAILED(rv)) return rv;  nsCOMPtr<nsISecurityPref> securityPref = do_QueryInterface(prefBranch, &rv); if (NS_SUCCEEDED(rv)) rv = securityPref->SecurityGetCharPref(pref, return_buf); return rv;
NS_IMETHODIMP nsPref::SecurityGetCharPref(const char *pref, char ** return_buf){  nsresult rv;  nsCOMPtr<nsIPrefBranch> prefBranch = do_QueryInterface(mPrefService, &rv);  if (NS_FAILED(rv))    return rv;  nsCOMPtr<nsISecurityPref> securityPref = do_QueryInterface(prefBranch, &rv);  if (NS_SUCCEEDED(rv))    rv = securityPref->SecurityGetCharPref(pref, return_buf);  return rv;}