child->GetNextSibling(&child);
child = child->GetNextSibling();
static nsIFrame* InitScrollbarFrame(nsIPresContext* aPresContext, nsIFrame* aCurrFrame, nsIScrollbarMediator* aSM){  // Check ourselves  nsCOMPtr<nsIScrollbarFrame> sf(do_QueryInterface(aCurrFrame));  if (sf) {    sf->SetScrollbarMediator(aSM);    return aCurrFrame;  }  nsIFrame* child;  aCurrFrame->FirstChild(aPresContext, nsnull, &child);  while (child) {    nsIFrame* result = InitScrollbarFrame(aPresContext, child, aSM);    if (result)      return result;    child->GetNextSibling(&child);  }  return nsnull;}