1316097 - Support easy favicon lookup

Status: RESOLVED DUPLICATE of bug 1315616

(WebExtensions :: General, defect)

Description

[Andy McKay]

Chrome supports a favicon lookup of the format:

chrome://favicon/<url>

I can't find much documentation on that, but its in quite a few add-ons as a match pattern in web_accessible_resources and permissions. It gives access to the favicon.

In Firefox we've got moz-anno:favicon: URLs

https://dxr.mozilla.org/mozilla-central/search?q=moz-anno&redirect=true

Which might be similar.

There's also bug 1315616 which suggests an API for getting the icon. 

If we go with moz-anno:favicon: URLs we'll end up with a different code path anyway from Chrome, unless we map chrome: to moz-anno:.

Finally: https://bugs.chromium.org/p/chromium/issues/detail?id=104102 mentions "Making chrome://favicon/ a host permission was a big mistake that has caused lots of heartache. ", but nothing seemed to change after that.