0533名無しさん＠お腹いっぱい。 (ﾜｯﾁｮｲ 3900-SGtB)
2017/09/20(水) 23:52:31.25ID:K9seZCIA0https://addons.mozilla.org/ja/firefox/addon/semi-full-screen/
How to enable legacy extensions in Firefox 57
https://www.ghacks.net/2017/08/12/how-to-enable-legacy-extensions-in-firefox-57/
