This is the closest to the spec behavior, I think, and less likely to
cause interop issues, but if you prefer me to stop the 'inheritance' chain at
contenteditable elements or what not I can also do that.
Differential Revision: https://phabricator.services.mozilla.com/D15963
--HG--
extra : moz-landing-system : lando
Emilio Cobos Álvarez