[CentOS] Firefox, C-7, and... reboot?

Wed Dec 2 17:02:27 UTC 2020
mark <m.roth at 5-cent.us>

Last night, for the second or third time since I upgraded from C6 to c7 
this summer, I did something on firefox - I think it was reload a page, 
and my system rebooted.

Yes, I have a ton of tabs open. I see nothing suspicious in 
/var/log/messages, or in /var/log/dmesg.old. I saw a mention of boltd? I 
think, but nothing more.

Has anyone else had this problem?