X11 access in content processes

[29edde2e]

Apparently this was fixed in Firefox 99, however it seems the gpu process still isn't enabled by default, so I'm not sure how they did it.
https://bugzilla.mozilla.org/show_bug.cgi?id=1129492

[DarkReaperBoy]

https://hg.mozilla.org/mozilla-central/rev/1edd1e4056e6