if (nsnull != mWindow) { mWindow->Invalidate(aForce); }  return NS_OK;
nsWebShell::Repaint(PRBool aForce){  /*  --dwc0001  NS_PRECONDITION(nsnull != mWindow, "null window");  */  if (nsnull != mWindow) {    mWindow->Invalidate(aForce);  }  return NS_OK;}