Kathleen Brade authored Aug 08, 2018 and Matthew Finkel committed Feb 05, 2021

Reuse the Firefox onboarding mechanism with minimal changes.
Localizable strings are pulled in from Torbutton (if Torbutton is
  not installed, we lack about:tor and no tour will be shown).
Replace SVG images with PNGs (see bug 27002),
For defense in depth, omit include OnboardingTelemetry.jsm entirely.
Added support for the following UITour page event:
  torBrowserOpenSecuritySettings

Also fix bug 27403: the onboarding bubble is not always displayed.

Arthur suggested to make the onboarding bubble visible on displays with
less than 960px width available, so we choose 200px instead.

Also fix bug 28628: Change onboarding Security panel to open new
Security Level panel.

Also fix bug 27484: Improve navigation within onboarding.

Bug 27082: enable a limited UITour

Disallow access to UITour functionality from all pages other than
  about:home, about:newtab, and about:tor.
Implement a whitelist mechanism for page actions.

Bug 26962 - implement new features onboarding (part 1...