Differential Revision: https://phabricator.services.mozilla.com/D55377

Differential Revision: https://phabricator.services.mozilla.com/D55380

…eConsts.h

Differential Revision: https://phabricator.services.mozilla.com/D55382

…nsts.h

Differential Revision: https://phabricator.services.mozilla.com/D55379

…zing border shorthand.

Differential Revision: https://phabricator.services.mozilla.com/D55588

…perty.

Differential Revision: https://phabricator.services.mozilla.com/D54722

Differential Revision: https://phabricator.services.mozilla.com/D55862

…n.enabled.

Differential Revision: https://phabricator.services.mozilla.com/D55898

Differential Revision: https://phabricator.services.mozilla.com/D55291

Differential Revision: https://phabricator.services.mozilla.com/D56043

Differential Revision: https://phabricator.services.mozilla.com/D55378

We need to ensure the rules that override all properties for scrollbar
part elements only apply to those that are NAC (and so will be eligible
for NAC style sharing).  We have some uses of non-NAC <scrollbar>
elements that should continue to inherit properties from their parents.

To avoid any changes in rule matching order that come with changing specificity,
we add a new :-moz-native-anonymous-no-specificity pseudo-class.

While we're here, we note :-moz-native-anonymous-no-specificity (and the
regular :-moz-native-anonymous pseudo-class) as not needing style
sharing cache revalidation, as we never share NAC styles.

Differential Revision: https://phabricator.services.mozilla.com/D56154

I was going to send a test for `:focus` via wpt, but then realized it was
probably not spec-compliant with the new rules people want to follow for
:focus, so I filed w3c/csswg-drafts#4555 instead.

Testing `:hover` / `:active` via wpt looked quite a bit of a hassle.

Differential Revision: https://phabricator.services.mozilla.com/D55591

This code comes from:

https://hg.mozilla.org/mozilla-central/rev/2418cfba72c33c5623f6fb4c243c5203819c8240

I audited other callers of write_str, they seem ok.

Differential Revision: https://phabricator.services.mozilla.com/D54601

…onsts.h

Differential Revision: https://phabricator.services.mozilla.com/D56203

This avoids the mutation due to the different serialization in some cases.

Differential Revision: https://phabricator.services.mozilla.com/D56732

Differential Revision: https://phabricator.services.mozilla.com/D56140

It's been enabled since Firefox 64.

Differential Revision: https://phabricator.services.mozilla.com/D56951

Font code is the only thing that was using Au in the style system without
interfacing with Gecko, and there was no real reason for it to do so.

This slightly simplifies the code.

Differential Revision: https://phabricator.services.mozilla.com/D57248

This is needed to support min() / max() / clamp(), etc.

Differential Revision: https://phabricator.services.mozilla.com/D57249

Differential Revision: https://phabricator.services.mozilla.com/D56044