Bug 41668 (Base Browser): Port the updater changes to base browser

Merge Info

Related Issues

• #41668 (closed)

Backport Timeline

• Immediate - patchsets for critical bug fixes or other major blocker (e.g. fixes for a 0-day exploit) OR patchsets with trivial changes which do not need testing (e.g. fixes for typos or fixes easily verified in a local developer build)
• Next Minor Stable Release - patchset that needs to be verified in nightly before backport
• Eventually - patchset that needs to be verified in alpha before backport
• No Backport - patchset for the next major stable

Upstream Merging

• Merge to base-browser - typically for !fixups to patches in the base-browser branch, though sometimes new patches as well
  • NOTE: if your changeset includes patches to both base-browser and tor-browser please please make separate merge requests for each part
  • This is the base browser part

Issue Tracking

• Link resolved issues with appropriate Release Prep issue for changelog generation

Change Description

Move to base browser some commits previously found in !568 (merged), !576 (merged), !577 (merged), !579 (merged) and !582 (merged) (the latter hasn't been approved/merged yet!).