Actions (wrap line, raw, history, permalink, go to code host) do not appear in repo-header toolbar in Firefox or Safari

Created by: emclain

• Sourcegraph version: 3.26.0 (locally-deployed on-prem version)
• Platform information: (all of the below tested on macOS Catalina):
  • Firefox (repro'ed in 87.0 (64-bit) and 88.0b6 (64-bit))
  • Safari version 14.0.3 (15610.4.3.1.7, 15610)
  • Bug does not repro in Google Chrome 90.0.4430.72 (Official Build) (x86_64)

Steps to reproduce:

1. Browse to a file in sourcegraph.

Expected behavior:

Buttons for wrap line, raw, history, permalink, go to code host are shown on the right side of the toolbar.

Actual behavior:

No buttons appear. No errors are seen in the JavaScript console.

If I shrink the window enough that it starts running out of room, an overflow menu does appear with these actions. However, when I expand the window again, the menu disappears.