Implement GridTemplateAreas with reference counting
Use `Arc` to implement refcounting for `GridTemplateAreas`
r? emilio
---
- [x] `./mach build -d` does not report any errors
- [x] `./mach test-tidy` does not report any errors
- [x] These changes fix#19428
- [x] These changes do not require tests
<!-- Reviewable:start -->
---
This change is [<img src="https://reviewable.io/review_button.svg" height="34" align="absmiddle" alt="Reviewable"/>](https://reviewable.io/reviews/servo/servo/19465)
<!-- Reviewable:end -->
Otherwise the serialisation wouldn't roundtrip with the new syntax, which fixes
the position of <overflow-position>.
Also make Servo and Gecko agree on whether to serialize "unsafe".
Bug: 1430817
MozReview-Commit-ID: L3GSMk5pZ3F
Add layout RPC query for getting an element's style
This enables us to implement Element::has_css_layout_box() in a more
direct way, and also enables us to remove some of the existing more
specific queries.
Fixes#19811.
r? @emilio
<!-- Reviewable:start -->
---
This change is [<img src="https://reviewable.io/review_button.svg" height="34" align="absmiddle" alt="Reviewable"/>](https://reviewable.io/reviews/servo/servo/19881)
<!-- Reviewable:end -->
This enables us to implement Element::has_css_layout_box() in a more
direct way, and also enables us to remove some of the existing more
specific queries.
Fixes#19811.
Otherwise removal of stylesheets may get out of sync with other DOM changes, and
we may fail to invalidate the style of the affected elements.
Bug: 1432850
Reviewed-by: bz
MozReview-Commit-ID: DrMTgLzQcnk
Use specific assertions
Similar to #19865
r? jdm
Note: Should I squash all the commits into one commit?
---
- [x] `./mach build -d` does not report any errors
- [x] `./mach test-tidy` does not report any errors
- [x] These changes do not require tests because it should not break anything
<!-- Reviewable:start -->
---
This change is [<img src="https://reviewable.io/review_button.svg" height="34" align="absmiddle" alt="Reviewable"/>](https://reviewable.io/reviews/servo/servo/19868)
<!-- Reviewable:end -->
style: make the try_match_ident_ignore_ascii_case macro actually return the error.
This allows it to be used as an expression, which I'd like to do very soon.
<!-- Reviewable:start -->
---
This change is [<img src="https://reviewable.io/review_button.svg" height="34" align="absmiddle" alt="Reviewable"/>](https://reviewable.io/reviews/servo/servo/19854)
<!-- Reviewable:end -->
Now that we have an Element around on cascade, we can stop using the cascade
flags mechanism to pass various element-related state, like "is this element the
root", or "should it use the item-based display fixup".
That fixes handwaviness in the handling of those flags from style reparenting,
and code duplication to handle tricky stuff like :visited.
There are a number of other changes that are worth noticing:
* skip_root_and_item_based_display_fixup is renamed to skip_item_display_fixup:
TElement::is_root() already implies being the document element, which by
definition is not native anonymous and not a pseudo-element.
Thus, you never get fixed-up if your NAC or a pseudo, which is what the code
tried to avoid, so the only fixup with a point is the item one, which is
necessary.
* The pseudo-element probing code was refactored to return early a
Option::<CascadeInputs>::None, which is nicer than what it was doing.
* The visited_links_enabled check has moved to selector-matching time. The rest
of the checks aren't based on whether the element is a link, or are properly
guarded by parent_style.visited_style().is_some() or visited_rules.is_some().
Thus you can transitively infer that no element will end up with a :visited
style, not even from style reparenting.
Anyway, the underlying reason why I want the element in StyleAdjuster is because
we're going to implement an adjustment in there depending on the tag of the
element (converting display: contents to display: none depending on the tag), so
computing that information eagerly, including a hash lookup, wouldn't be nice.
This more concrete wrapper type can write a prefix the very first time something
is written to it. This allows removing plenty of useless monomorphisations caused
by the former W/SequenceWriter<W> pair of types.
