It seems this API was the original way of checking if an add-on was in the blocklist. Then we ended up with different blocklist states ("soft block"), in bug 455906 (1.9.1!), which needed a more finegrained result out of the blocklist. At that point there were still a few consumers of the old API (and of course we had xpcom add-ons to think of). By Fx4 / mozilla2.0, only 3 non-test consumers were left. All 3 were for update-related addon compat checks. They were removed in bug 1262880 (Firefox 49). AFAICT rather than making an async equivalent, we can just nuke this API from orbit.

Link for mozilla2.0 results: https://dxr.mozilla.org/mozilla2.0/search?q=isaddonblocklisted

I'll probably need to rebase after the renames in bug 1449255, but that shouldn't overly influence the review/patch here.

(In reply to :Gijs (he/him) from comment #3) > I'll probably need to rebase after the renames in bug 1449255, but that > shouldn't overly influence the review/patch here. Rebased patch incoming.

Comment on attachment 8965255 [details] Bug 1451487 - remove nsIBlocklistService::isAddonBlocklisted as it's unused, https://reviewboard.mozilla.org/r/233972/#review239736

Pushed by gijskruitbosch@gmail.com: https://hg.mozilla.org/integration/autoland/rev/4b5ca5e0be5c remove nsIBlocklistService::isAddonBlocklisted as it's unused, r=mossop