ThinArc is way more complex than it needs to be, and miri complains
about various things when using the selectors crate with it.

This doesn't fully fix miri, but it gets much closer. ThinArc becomes
just an alias for Arc<HeaderSlice<>>. This allows to simplify the
bindings to ArcSlice too, since now the existing Arc<> code can just be
used.

Differential Revision: https://phabricator.services.mozilla.com/D183011

Introduce LineWidth (which doesn't snap) and let BorderSideWidth
wrap it and actually do the snapping.

Differential Revision: https://phabricator.services.mozilla.com/D180845

Now it supports "normal" keyword. Also, offset-position doesn't create
stacking context and it doesn't have offset transform, so we can
simplify CompareMotionValues() a little bit.

Note: We don't have to add test in [1] because Blink added one to WPT
upstream repo already.

[1] css/motion/parsing/offset-position-parsing-valid.html

Note: the usage of offset-position is in other bugs.

Differential Revision: https://phabricator.services.mozilla.com/D179623

And add some bindings support to it, which will be used by the next
patch.

Differential Revision: https://phabricator.services.mozilla.com/D178768

$ find servo -name '*.rs' | xargs rustup run nightly rustfmt

Depends on D179380

Differential Revision: https://phabricator.services.mozilla.com/D179381

Use from_bits_retain where possible to save a few instructions here and there
while at it.

Differential Revision: https://phabricator.services.mozilla.com/D179379

Anything that doesn't need interior mutability doesn't need Locked<>
around it.

Depends on D179059

Differential Revision: https://phabricator.services.mozilla.com/D179060

This makes me a bit less uncomfortable about the previous changes :)

Note that some of this code gets modified in the following patch.

Differential Revision: https://phabricator.services.mozilla.com/D179059

Depends on D179038

Differential Revision: https://phabricator.services.mozilla.com/D179039

Differential Revision: https://phabricator.services.mozilla.com/D179038

This is necessary to properly report changes in our document.

The remaining failures are about change event scheduling, which is a
pre-existing issue. Will fix, but in a separate bug.

Differential Revision: https://phabricator.services.mozilla.com/D178917

Bug 1833540 - [css-properties-values-api] Implement parsing and serialization for @property at-rule r=emilio

Implemented behind the new properties-and-values pref.

Support for the CSSPropertyRule WebIDL interface is also added in this
patch, because until it's added, any attempt to access the rule using
the CSSOM would crash the browser.

Depends on D178268

Differential Revision: https://phabricator.services.mozilla.com/D178270

Bug 1815186 - Add ColorTo to InspectorUtils to convert color to other color spaces. r=emilio,layout-reviewers,supply-chain-reviewers

This will allow calling `InspectorUtils.ColorTo("red", "lab")` and
receive `{color: "lab(54.3 80.8 69.9)", components: [54.3, 80.8, 69.9, 1.0], adjusted: false}`.

The adjusted value is always "false", because gamut checking and mapping
is not supported at the moment. See:
https://bugzilla.mozilla.org/show_bug.cgi?id=1823363

Differential Revision: https://phabricator.services.mozilla.com/D169942

Bug 1833536 - [css-nesting] Do a first pass at parsing nested rules mixed with declarations. r=tlouw

Plumb everything up. This factors out declaration and rule parsing so
we share the code with the regular declaration parser.

This could be made a bit nicer in the future. We need to decide what to
do for @page and @keyframe (it seems conditional rules inside ought to
work, but that's not so easy because per spec we create a nested style
rule).

But this is a first pass that passes a good chunk of the tests. There
are other fixups to cssom, and I think some of the tests we fail are
actually wrong...

Differential Revision: https://phabricator.services.mozilla.com/D178266

This is a relatively small code size regression (130k on windows and
macOS, 180k on Linux), for a few high confidence improvements in
speedometer 3. See link in the bug.

If this sticks, we can actually clean up a bunch of code, and eventually
unify RefPtr and nsCOMPtr. But I want this to be on the tree for a while
before doing more aggressive refactorings / actually removing the code.

Differential Revision: https://phabricator.services.mozilla.com/D178267

Differential Revision: https://phabricator.services.mozilla.com/D173884

Backed out 3 changesets (bug 1809568) for causing build bustages in layout/generic/nsLineLayout.cpp CLOSED TREE

Backed out changeset 6c5bbcbafce9 (bug 1809568)
Backed out changeset b518133a5c34 (bug 1809568)
Backed out changeset 2407088e9b49 (bug 1809568)

Differential Revision: https://phabricator.services.mozilla.com/D173884

Backed out 3 changesets (bug 1809568) for causing node devtools failures in devtools/client/debugger/src/components/test/QuickOpenModal.spec.js CLOSED TREE

Backed out changeset 56ce741da8f5 (bug 1809568)
Backed out changeset 5a91ce4870e4 (bug 1809568)
Backed out changeset cc00422f050a (bug 1809568)

Differential Revision: https://phabricator.services.mozilla.com/D173884

This changes the cssparser setup to:

 * Avoid having to do copies of the ParsingContext all over the place,
   which is useful because I plan to stash more nesting state in there.

 * Use the new RuleBodyParser which allows parsing qualified rules,
   declarations, and so on. Though we still don't use this anywhere.

The next step is to join NestedRuleParser and PropertyDeclarationParser,
so that we can parse declarations in a lot of the nested rules as well.

Differential Revision: https://phabricator.services.mozilla.com/D178053

Backed out changeset 7abf96264256 (bug 1833151) for causing multiple failures e.g. 431948-1.html and test_font_feature_values_parsing.html. CLOSED TREE

This changes the cssparser setup to:

 * Avoid having to do copies of the ParsingContext all over the place,
   which is useful because I plan to stash more nesting state in there.

 * Use the new RuleBodyParser which allows parsing qualified rules,
   declarations, and so on. Though we still don't use this anywhere.

The next step is to join NestedRuleParser and PropertyDeclarationParser,
so that we can parse declarations in a lot of the nested rules as well.

Differential Revision: https://phabricator.services.mozilla.com/D178053

So that they aren't imported via #[path]. This allows cargo to see them
even before building.

Differential Revision: https://phabricator.services.mozilla.com/D178105

Backed out changeset e862b1560caa (bug 1809568)
Backed out changeset 0a20b91de67b (bug 1809568)
Backed out changeset 6060fc7d49d4 (bug 1809568)

Differential Revision: https://phabricator.services.mozilla.com/D173884

Use the actual Locked<T> types around (via a typedef, just for
convenience).

Differential Revision: https://phabricator.services.mozilla.com/D177824

Backed out changeset f6e3d050b3e7 (bug 1832173) for causing bustages at CanvasRenderingContext2D.cpp. CLOSED TREE

Use the actual Locked<T> types around (via a typedef, just for
convenience).

Differential Revision: https://phabricator.services.mozilla.com/D177824

See previous patches for context.

Differential Revision: https://phabricator.services.mozilla.com/D177622

See blocked bug.

For non-Locked types we can just use the same underlying type at the FFI
boundary. Port StylesheetContents and CssUrlData to this set-up.
CssUrlData is already generated by cbindgen anyways.

Differential Revision: https://phabricator.services.mozilla.com/D177559

This should allow making these work on canvas.

Differential Revision: https://phabricator.services.mozilla.com/D177074

Avoid trying to resolve a currentcolor when a foreground color is not
available.

Differential Revision: https://phabricator.services.mozilla.com/D177368

After the previous patches we only have one trait which we should also
tweak / rework, so let's put it all on that single trait.

Differential Revision: https://phabricator.services.mozilla.com/D177515

Backed out changeset 1260faa596e0 (bug 1832065)
Backed out changeset c64412c2e6fe (bug 1832065)

After the previous patches we only have one trait which we should also
tweak / rework, so let's put it all on that single trait.

Depends on D177497

Differential Revision: https://phabricator.services.mozilla.com/D177515

HasBoxFFI and HasArcFFI aren't great, see bug 1831242 as for examples of
why.

HasArcFFI requires a bit more care, but HasBoxFFI doesn't give us much
benefit. Instead use the same type in the FFI boundary.

Differential Revision: https://phabricator.services.mozilla.com/D177252

Bug 18307460 - Rework -x-text-zoom to allow disabling text zoom and min-font-size separately. r=jfkthame,layout-reviewers

And use it instead of explicit document checks. This centralizes where
we check for it.

IsChromeDoc is relatively cheap, but this bug wants to also check for
PDF.js which is a bit more expensive.

No behavior change.

Differential Revision: https://phabricator.services.mozilla.com/D176940

Refactored ImportLayer into an enum instead of a struct and using
Option everywhere.

Differential Revision: https://phabricator.services.mozilla.com/D176793