mozilla/addon-sdk — pull request #1300 by gijsk (2013-11-21 00:54:24+00:00)
Title: Bug 854226 - keep check of widgets having been inserted by id, r?zer0

So the test in question about the add-on bar is thoroughly broken. I've added assertions that prove this and disabled the test completely because I don't think it's worth fixing as we'll be getting rid of this code in 0-2 cycles anyway. Let's just focus on the future instead of the past.