Shell freezes and rapidly consumes all memory after holding down F11 in Firefox

Shell freezes and rapidly consumes all memory after holding down F11 in Firefox for a second. This seems to happen in both Wayland and Xorg sessions..

PID  USER PR NI VIRT   RES    SHR    S %CPU %MEM TIME+   COMMAND
13113 dan 20 0 12.947g 7.897g 7.788g R 91.0 51.5 1:00.90 gnome-shell
13773 dan 20 0 2169752 277244 142700 S 46.2 1.7 0:17.66 firefox
13832 dan 20 0 2039840 165760 109716 S 28.6 1.0 0:10.49 Web Content
13132 dan 20 0 1241100 241772 220172 S 13.3 1.5 0:09.01 Xwayland

You can then unfreeze it by killing firefox from ssh.

Downstream bug: https://bugs.launchpad.net/bugs/1749779