Convert Firefox extension to a WebExtension

[jaredhirsch]

Firefox is moving to WebExtensions in 2017, and will be removing non-WebExtensions from AMO by the end of the year, in FF 57.

The https-everywhere code should get much simpler, since the same APIs that power the Chrome extension code should work on Firefox. While the WebExtension APIs aren't all supported yet, I think the pieces used by https-everywhere are:

• requests can be intercepted using the webRequest and webNavigation APIs
• the toolbar button can be wired up using the browserAction API
• the popup contents can be written as simple HTML, and specified in the manifest.json file's browser_action.default_popup config
• all the permissions requested by the https-everywhere WebExtension are supported

Looking through the known incompatibilities between FF and Chrome, I didn't immediately see any blockers--but I'm not super familiar with this code, so maybe I've missed something. There's another page which lists known issues. Again, I don't see any blockers, but someone more familiar with the Chrome code should take a look.

So, yeah. Should be really satisfying to mass-delete all that weird XUL and XPCOM stuff. Want some help getting things ported over?

[Bisaloo]

see #7389 and #2640

[jeremyn]

Thanks @6a68. I'm closing this issue as a duplicate of the issues that @Bisaloo mentions, but I'm pinging @Hainish so he is aware of your specific interest in this migration.

[jaredhirsch]

thanks!