While we do fail a couple of tests, the other mainstream browsers also fail them and I think our implementation of tab-size is good enough to be unprefixed at this point. Having this patch also makes testing easier.
This CSS property allows input carets (that blinking input cursor you see in text fields), to be given a custom color. This was implemented in Firefox 53, and it was such a minor feature that no one ever missed it, but I don't see any harm in implementing this.
https://bugzilla.mozilla.org/show_bug.cgi?id=1063162
This stub is added because websites insist on considering this
very hardware-dependent and O.S.-variable low-level font-control
as a "critical feature" which it isn't as there is 0 guarantee
that font variation settings are supported or honored by any
operating system used by the client.
On top this is a WD status feature that sites shouldn't be using, and
the feature itself is strongly discouraged for use in favor of standard
CSS font manipulation keywords like `font-weight`.
