if (!context) { return NS_ERROR_OUT_OF_MEMORY; }  return CallQueryInterface(context, aInstancePtrResult);
if (context) context->AddRef(); return context;
NS_NewStyleContext(nsIStyleContext** aInstancePtrResult,                   nsIStyleContext* aParentContext,                   nsIAtom* aPseudoTag,                   nsRuleNode* aRuleNode,                   nsIPresContext* aPresContext){  NS_PRECONDITION(nsnull != aInstancePtrResult, "null ptr");  if (nsnull == aInstancePtrResult) {    return NS_ERROR_NULL_POINTER;  }  nsStyleContext* context = new (aPresContext) nsStyleContext(aParentContext, aPseudoTag,                                                               aRuleNode, aPresContext);  if (!context) {    return NS_ERROR_OUT_OF_MEMORY;  }  return CallQueryInterface(context, aInstancePtrResult);}