return NS_OK;
DocumentViewerImpl::CallChildren(CallChildFunc aFunc, void* aClosure){  nsCOMPtr<nsIDocShellTreeNode> docShellNode(do_QueryInterface(mContainer));  if (docShellNode)  {    PRInt32 i;    PRInt32 n;    docShellNode->GetChildCount(&n);    for (i=0; i < n; i++)    {      nsCOMPtr<nsIDocShellTreeItem> child;      docShellNode->GetChildAt(i, getter_AddRefs(child));      nsCOMPtr<nsIDocShell> childAsShell(do_QueryInterface(child));      NS_ASSERTION(childAsShell, "null child in docshell");      if (childAsShell)      {        nsCOMPtr<nsIContentViewer> childCV;        childAsShell->GetContentViewer(getter_AddRefs(childCV));        if (childCV)        {          nsCOMPtr<nsIMarkupDocumentViewer> markupCV = do_QueryInterface(childCV);          if (markupCV) {            (*aFunc)(markupCV, aClosure);          }        }      }    }  }  return NS_OK;}