nsIPresShell *presShell = GetOwnerDoc()->GetShellAt(0);
nsIPresShell *presShell = doc->GetShellAt(0);
nsSVGSVGElement::ForceRedraw(){  if (!IsInDoc()) return NS_ERROR_FAILURE;  nsIPresShell *presShell = GetOwnerDoc()->GetShellAt(0);  NS_ASSERTION(presShell, "need presShell to unsuspend redraw");  if (!presShell) return NS_ERROR_FAILURE;  nsIViewManager* vm = presShell->GetViewManager();  NS_ASSERTION(vm, "need viewmanager to unsuspend redraw");  if (!vm) return NS_ERROR_FAILURE;  vm->EnableRefresh(NS_VMREFRESH_IMMEDIATE);  return NS_OK;}