cN->ChildCount(numChildren);
if (aRoot) { nsCOMPtr<nsIContent> cN = aRoot; nsCOMPtr<nsIContent> cChild; PRInt32 numChildren;  cN->ChildCount(numChildren);
nsCOMPtr<nsIContent> nsContentIterator::GetDeepLastChild(nsCOMPtr<nsIContent> aRoot){  if (!aRoot)     return aRoot;      nsCOMPtr<nsIContent> cN = aRoot;  nsCOMPtr<nsIContent> cChild;  PRInt32 numChildren;    cN->ChildCount(numChildren);  while ( numChildren )  {    cN->ChildAt(--numChildren,*getter_AddRefs(cChild));    if (cChild)    {      cChild->ChildCount(numChildren);      cN = cChild;    }    else    {      break;    }  }  return cN;}