Backed out 9 changesets (aec1be189f68, f9c2e5707d43, fe82d67b63ef, 07004e2608f3, f6022837406b, 36fc4e06713d, 30718580670d, 82242b2d942d, 5cd51f055a1a) due to reported regressions.
Differential Revision: https://phabricator.services.mozilla.com/D212435
bugzilla-url: https://bugzilla.mozilla.org/show_bug.cgi?id=385615
gecko-commit: 709248f1fc694bd5312372e9f13c9cced7860e2b