vm->EnableRefresh();
vm->EnableRefresh(NS_VMREFRESH_IMMEDIATE);
HTMLContentSink::RefreshIfEnabled(nsIViewManager* vm){  if (vm) {    nsIContentViewer* contentViewer = nsnull;    nsresult rv = mWebShell->GetContentViewer(&contentViewer);    if (NS_SUCCEEDED(rv) && (contentViewer != nsnull)) {      PRBool enabled;      contentViewer->GetEnableRendering(&enabled);      if (enabled) {        vm->EnableRefresh();      }      NS_RELEASE(contentViewer);     }  }  return NS_OK;}