Intent to implement and ship: CSS counter-set property

[Mats Palmgren]

Summary:
The counter-set CSS property assigns an absolute value to a CSS counter.
(It behaves the same as counter-increment but assigns instead of
increments.)

It will be used internally to map <li value=N> to set the value of
the built-in 'list-item' counter (see separate announcement following
this).

Bug:
https://bugzilla.mozilla.org/show_bug.cgi?id=1518201

Link to standard:
https://drafts.csswg.org/css-lists/#propdef-counter-set

Platform coverage: All platforms

Estimated or target release: Firefox 68

Preference behind which this will be implemented: none

DevTools bug: none

Do other browser engines implement this?
No, as far as I know.

web-platform-tests:
I added some under css/css-lists/. (It will also be tested
indirectly through <li value=N>.)

Is this feature restricted to secure contexts? No


/Mats

[Mats Palmgren]