And source code helpfully found by some other commenters: https://github.com/mozilla/gecko-dev/tree/master/browser/extensions/webcompat/shims https://github.co

And source code helpfully found by some other commenters: https://github.com/mozilla/gecko-dev/tree/master/browser/extensions/webcompat/shims https://github.com/mozilla/gecko-dev/tree/master/browser/ext...