scrollFrame->GetScrollPreference(aBoxLayoutState.GetPresContext(), &scrollPref);
scrollFrame->GetScrollPreference(aBoxLayoutState.PresContext(), &scrollPref);
nsListboxScrollPortFrame::GetPrefSize(nsBoxLayoutState& aBoxLayoutState, nsSize& aSize){    nsIBox* child = nsnull;  GetChildBox(&child);   nsresult rv = child->GetPrefSize(aBoxLayoutState, aSize);  nsListBoxBodyFrame* outer = NS_STATIC_CAST(nsListBoxBodyFrame*,child);  PRInt32 size = outer->GetFixedRowSize();  if (size > -1)    aSize.height = size*outer->GetRowHeightTwips();     nsCOMPtr<nsIScrollableFrame> scrollFrame(do_QueryInterface(mParent));  if (scrollFrame) {    nsIScrollableFrame::nsScrollPref scrollPref;    scrollFrame->GetScrollPreference(aBoxLayoutState.GetPresContext(), &scrollPref);    if (scrollPref == nsIScrollableFrame::Auto) {      nsMargin scrollbars = scrollFrame->GetDesiredScrollbarSizes(&aBoxLayoutState);      aSize.width += scrollbars.left + scrollbars.right;    }  }  AddMargin(child, aSize);  AddBorderAndPadding(aSize);  AddInset(aSize);  nsIBox::AddCSSPrefSize(aBoxLayoutState, this, aSize);  return rv;}