aResult = mHistory.Count(); return NS_OK;
NS_ENSURE_STATE(mSessionHistory); NS_ENSURE_TRUE(!IsFrame(), NS_ERROR_FAILURE);  NS_ENSURE_SUCCESS(mSessionHistory->GetCount(&aResult), NS_ERROR_FAILURE); return NS_OK;
nsWebShell::GetHistoryLength(PRInt32& aResult){  aResult = mHistory.Count();  return NS_OK;}