const nsAReadableString& aPseudoElt,
const nsAString& aPseudoElt,
nsComputedDOMStyle::Init(nsIDOMElement *aElement,                         const nsAReadableString& aPseudoElt,                         nsIPresShell *aPresShell){  NS_ENSURE_ARG_POINTER(aElement);  NS_ENSURE_ARG_POINTER(aPresShell);  mPresShellWeak = getter_AddRefs(NS_GetWeakReference(aPresShell));  mContent = do_QueryInterface(aElement);  if (!mContent) {    // This should not happen, all our elements support nsIContent!    return NS_ERROR_FAILURE;  }  if(!DOMStringIsNull(aPseudoElt) && !aPseudoElt.IsEmpty()) {    mPseudo = dont_AddRef(NS_NewAtom(aPseudoElt));    NS_ENSURE_TRUE(mPseudo, NS_ERROR_OUT_OF_MEMORY);  }  nsCOMPtr<nsIPresContext> presCtx;  aPresShell->GetPresContext(getter_AddRefs(presCtx));  NS_ENSURE_TRUE(presCtx, NS_ERROR_FAILURE);  presCtx->GetTwipsToPixels(&mT2P);  return NS_OK;}