Differential Revision: https://phabricator.services.mozilla.com/D42087

These two bugs (bug 1572738 and bug 1572451) are stylo regressions.

When font-family changes, we try to recompute the font-size with a length /
percentage combinations in case the generic family changes, so the user
preferences are kept.

When calc() is involved, we clamp to non-negative too early, via
NonNegativeLength::scale_by.

I think we should generally dump this "try to track font-size across calc()"
thingie, as as various comments note it is not quite perfect, and it's not clear
how it should work in presence of min()/max().

This patch fixes the issue and simplifies code a bit, I may consider removing
this altogether in a follow-up.

Differential Revision: https://phabricator.services.mozilla.com/D41776

Differential Revision: https://phabricator.services.mozilla.com/D42586

Differential Revision: https://phabricator.services.mozilla.com/D42552

Differential Revision: https://phabricator.services.mozilla.com/D42857

Differential Revision: https://phabricator.services.mozilla.com/D42859

This is consistent with the `order` property anyhow, and allows to simplify some
code.

Negatives are still not parsed, but rust uses a similar representation for all
CSS <integer> values and so should C++.

Differential Revision: https://phabricator.services.mozilla.com/D42912

Differential Revision: https://phabricator.services.mozilla.com/D42913

Differential Revision: https://phabricator.services.mozilla.com/D42914

Differential Revision: https://phabricator.services.mozilla.com/D43400

-moz-appearance uses cbindgen since a long time ago.

Differential Revision: https://phabricator.services.mozilla.com/D43472

This also fixes some of the issues with -moz-image-region, where we just minted
an auto out of the blue.

Differential Revision: https://phabricator.services.mozilla.com/D43474

This cleans up the pattern of "Use a private dtor so that the helper functions
do the right thing" by enabling it everywhere using:

  mozilla/cbindgen#377

It also caught some uninitialized value issues.

I think they're mostly harmless since we zero-initialize our structs:

https://searchfox.org/mozilla-central/rev/325c1a707819602feff736f129cb36055ba6d94f/servo/components/style/properties/gecko.mako.rs#632

And since we override the clip rect, which is the other bit of code that was
failing to build with this change.

Differential Revision: https://phabricator.services.mozilla.com/D43491

… <aspect-ratio>.

Differential Revision: https://phabricator.services.mozilla.com/D41557

…ter()/counters().

CSSWG resolution:
w3c/csswg-drafts#4163 (comment)

Spec:
https://drafts.csswg.org/css-lists-3/#counter-functions

Differential Revision: https://phabricator.services.mozilla.com/D43893

For developing properties, we will handle them in an other bug.

Besides, I use an iframe for the test because we create a use counter in
the constructor of Document, which use the prefs to decide what kind of
properties we want to record. So, in the test, we have to reload iframe
to make sure we re-create the document, so does the use counter, to make
sure the prefs work properly.

The two prefs affect the css use counters:
1. layout.css.use-counters.enabled: Allocate use counters, and record
   non-custom properties.
2. layout.css.use-counters-unimplemented.enabled: Record all unimplmented
   properties into the use counters.

If we disable layout.css.use-counters.enblaed, we don't create use counters
object, so layout.css.use-counters-unimplemented.enabled doesn't work,
either.

Differential Revision: https://phabricator.services.mozilla.com/D43860

Differential Revision: https://phabricator.services.mozilla.com/D43992

Differential Revision: https://phabricator.services.mozilla.com/D44403

Differential Revision: https://phabricator.services.mozilla.com/D44412

We are trying to not serialize `text-decoration-line: none` if there are other
non-default values for the longhands.

Differential Revision: https://phabricator.services.mozilla.com/D44908

Stylo's Gecko wrapper duplicated some logic from the C++ side so
that the Rust compiler would be able to optimize better. Now that
we have xLTO, this kind of manual inlining should not be neccessary
anymore.

Differential Revision: https://phabricator.services.mozilla.com/D43765

… atom table elsewhere.

Differential Revision: https://phabricator.services.mozilla.com/D44217