nsString newStyle; if (aVisible) newStyle = ""; else newStyle = "hidden";  if (oldStyle != newStyle) child->SetAttribute(kNameSpaceID_None, nsHTMLAtoms::value, newStyle, PR_TRUE);
nsCOMPtr<nsIScrollbarFrame> scrollbar(do_QueryInterface(aScrollbar)); if (scrollbar) {  nsCOMPtr<nsIScrollbarMediator> mediator; scrollbar->GetScrollbarMediator(getter_AddRefs(mediator)); if (mediator) {  mediator->VisibilityChanged(scrollbar, aVisible); } }
nsGfxScrollFrameInner::SetScrollbarVisibility(nsIFrame* aScrollbar, PRBool aVisible){        nsString oldStyle = "";        nsCOMPtr<nsIContent> child;        aScrollbar->GetContent(getter_AddRefs(child));        child->GetAttribute(kNameSpaceID_None, nsHTMLAtoms::value, oldStyle);        nsString newStyle;        if (aVisible)          newStyle = "";        else          newStyle = "hidden";        if (oldStyle != newStyle)            child->SetAttribute(kNameSpaceID_None, nsHTMLAtoms::value, newStyle, PR_TRUE);}