NS_PRECONDITION(0 != mRefCnt, "dup release"); --mRefCnt; if (mRefCnt == 0) { NS_DELETEXPCOM(this); return 0;
if (--mRefCnt == 0) { delete this; return 0;
NS_IMETHODIMP_(nsrefcnt) nsWebShell::Release(void){  NS_PRECONDITION(0 != mRefCnt, "dup release");  --mRefCnt;  if (mRefCnt == 0) {    NS_DELETEXPCOM(this);    return 0;  }  return mRefCnt;}