nsMathMLmsubFrame* it = new nsMathMLmsubFrame;
nsMathMLmsubFrame* it = new (aPresShell) nsMathMLmsubFrame;
NS_NewMathMLmsubFrame(nsIFrame** aNewFrame){  NS_PRECONDITION(aNewFrame, "null OUT ptr");  if (nsnull == aNewFrame) {    return NS_ERROR_NULL_POINTER;  }  nsMathMLmsubFrame* it = new nsMathMLmsubFrame;  if (nsnull == it) {    return NS_ERROR_OUT_OF_MEMORY;  }  *aNewFrame = it;  return NS_OK;}