mozilla/browserid — pull request #3736 by 6a68 (2013-07-30 16:22:00+00:00)
Title: Add arrow overlap to avoid animation flicker. Fixes #3668.

@seanmonstar mind looking?

I'm not sure if I should reposition `.arrow` or `.arrowContainer`, but this works, meh.

Yay webkit CSS subpixel rounding errors during transition of adjacent els.