This patch was generated by my modeline.py script.
MozReview-Commit-ID: EbVjPLwiUAT
Depends on D4159
Differential Revision: https://phabricator.services.mozilla.com/D4161
--HG--
extra : moz-landing-system : lando
This API is not implemented by other browsers and we want to ensure
there isn't significant usage before removing it.
MozReview-Commit-ID: Kb3HyJW6hGB
--HG--
extra : rebase_source : deb7013ef20194fa9282dbe4390d37e8c2efc68e