Bug 281743. Don't mess around with vestigial GTK2 widgets. r+sr=blizzard, a=dbaron

    NS_ASSERTION(!mContainer, "Expected Mozilla child widget");

    // We skip the nsWindows that don't have mDrawingareas.

    // These are probably in the process of being destroyed.

    if (!GetNextSibling()) {

        // We're to be on top.

        if (mDrawingarea)

            gdk_window_raise(mDrawingarea->clip_window);

    } else {

        // All the siblings before us need to be below our widget. 

        for (nsWindow* w = this; w;

             w = NS_STATIC_CAST(nsWindow*, w->GetPrevSibling())) {

            if (w->mDrawingarea)

                gdk_window_lower(w->mDrawingarea->clip_window);

        }

    }