FWIW, Firefox Dev Ed &#x2F; Aurora has had this for a while and has been on 47 since 08 March.<p><a href="https:&#x2F;&#x2F;www.mozilla.org&#x2F;en-US&#x2F;firefox&#x2F;47.0a2&#x2F;releasenotes&#x2F;" rel="nofollow">https:&#x2F;&#x2F;www.mozilla.org&#x2F;en-US&#x2F;firefox&#x2F;47.0a2&#x2F;releasenotes&#x2F;</a>