由 Aleksandr Seleznev （開發者） 發表於 Oct. 24, 2017 · 永久網址

Web Extension API doesn't provide any way to hide titlebar. You can try to use external process via Native Messaging API, but it isn't good solution (a very bad hack actually) and will have complicated installation instruction. I have no plan to make it.

Mozilla Firefox will have native support for CSD soon (not sure that it will be shipped in Fx 57). You can track progress in https://bugzilla.mozilla.org/show_bug.cgi?id=1283299 and help with testing for example.