NS_PRECONDITION(nsLayoutAtoms::fixedList == aListName, "unexpected child list"); if (aListName != nsLayoutAtoms::fixedList) {
if (mFixedContainer.GetChildListName() == aListName) { rv = mFixedContainer.InsertFrames(this, aPresContext, aPresShell, aListName, aPrevFrame, aFrameList); } else {
ViewportFrame::InsertFrames(nsIPresContext* aPresContext,                          nsIPresShell&   aPresShell,                          nsIAtom*        aListName,                          nsIFrame*       aPrevFrame,                          nsIFrame*       aFrameList){  nsresult  rv;  NS_PRECONDITION(nsLayoutAtoms::fixedList == aListName, "unexpected child list");  if (aListName != nsLayoutAtoms::fixedList) {    // We only expect incremental changes for our fixed frames    rv = NS_ERROR_INVALID_ARG;  } else {    // Insert the new frames#ifdef NS_DEBUG    nsFrame::VerifyDirtyBitSet(aFrameList);#endif    mFixedFrames.InsertFrames(nsnull, aPrevFrame, aFrameList);      // Generate a reflow command to reflow the dirty frames    nsIReflowCommand* reflowCmd;    rv = NS_NewHTMLReflowCommand(&reflowCmd, this, nsIReflowCommand::ReflowDirty);    if (NS_SUCCEEDED(rv)) {      reflowCmd->SetChildListName(nsLayoutAtoms::fixedList);      aPresShell.AppendReflowCommand(reflowCmd);      NS_RELEASE(reflowCmd);    }  }  return rv;}