window flags sync issue between QWindown and platform window

void QXcbWindow::setWindowFlags(Qt::WindowFlags flags)
{
    if (shouldDeferTask(Task::SetWindowFlags))
        return;

    Qt::WindowType type = static_cast<Qt::WindowType>(int(flags & Qt::WindowType_Mask));

    if (type == Qt::ToolTip)
        flags |= Qt::WindowStaysOnTopHint | Qt::FramelessWindowHint | Qt::X11BypassWindowManagerHint;
    if (type == Qt::Popup)
        flags |= Qt::X11BypassWindowManagerHint;