if (childList == nsnull) { childList = lastChild = aChild; } else { lastChild->SetNextSibling(aChild); lastChild = aChild; }
nsFrameState  frameState;   aChild->GetFrameState(&frameState); aChild->SetFrameState(frameState | NS_FRAME_OUT_OF_FLOW); nsFrameItems::AddChild(aChild);
nsFrameItems::AddChild(nsIFrame* aChild){  if (childList == nsnull) {    childList = lastChild = aChild;  }  else  {    lastChild->SetNextSibling(aChild);    lastChild = aChild;  }}