Intent to ship: CSS paint-order for HTML text

[Jonathan Kew]

As of Firefox 60, I intend to turn CSS paint-order for HTML text on by
default. It has been developed behind the layout.css.paint-order.enabled
preference.

I am not aware of any other UAs yet shipping this feature, but since our
intent to implement, the CSS WG has agreed to include this in the "CSS
Fill and Stroke Module Level 3" spec:
https://drafts.fxtf.org/fill-stroke/#strokes
https://github.com/w3c/fxtf-drafts/issues/107
https://lists.w3.org/Archives/Public/www-style/2018Jan/0004.html

Bug to turn on by default:
https://bugzilla.mozilla.org/show_bug.cgi?id=1435684

This feature was previously discussed in this "intent to implement" thread:

https://groups.google.com/forum/#!topic/mozilla.dev.platform/mogT087VmJM.

The feature was implemented in
https://bugzilla.mozilla.org/show_bug.cgi?id=1426146
including a web-platform-test to confirm it is working as expected.