mOldChildCount(aOldChildCount), mParent(aParent), mDocument(aDocument)
mOldChildCount(aOldChildCount), mChildrenBound(0), mParent(aParent), mDocument(aDocument)
  nsFragmentObserver(PRUint32 aOldChildCount, nsIContent* aParent,                     nsIDocument* aDocument) :    mOldChildCount(aOldChildCount), mParent(aParent), mDocument(aDocument)  {    NS_ASSERTION(mParent, "Must have parent!");  }