https://blog.wongcw.com/2019/12/06/firefox-nightly%e7%82%ba%e7%95%ab%e4%b8%ad%e7%95%ab%e8%a6%96%e9%a0%bb%e7%aa%97%e5%8f%a3%e6%b7%bb%e5%8a%a0%e4%ba%86%e9%9d%9c%e9%9f%b3%e6%8c%89%e9%88%95/
Firefox Nightly為畫中畫視頻窗口添加了靜音按鈕