### Changes made
This implements named grid lines (line names in `grid-template-*`),
named grid areas (`grid-template-areas`), and the ability to target
those using `grid-{row,column}-{start,end}`. It also includes a bunch of
miscelaneous fixes for `repeat(auto-fill | auto-fit, ...)` syntax as
that interacts with the specification of line names.
The actual layout implementation is in Taffy. The bulk of this PR is
updating Servo to translate (CSS Grid-related) Stylo types into Taffy
types using a new iterator-based API which uses iterators and lazy
translation for efficiency (which is more important now that we're
dealing with string data, even though they're `Atom`s).
### Testing
This functionality has lots of WPT tests. It fixes some seemingly random
CSS Grid tests that use named lines/areas even though that's not what
they're testing.
### Screenshots
wikipedia.org
<img width="1624" height="1056" alt="Screenshot 2025-07-27 at 20 03 16"
src="https://github.com/user-attachments/assets/2c50b96f-ae36-4405-ac48-b771bfdcb515"
/>
bbc.co.uk:
<img width="1624" height="1056" alt="Screenshot 2025-07-27 at 20 32 57"
src="https://github.com/user-attachments/assets/ba84e211-65d2-4411-95fb-7b9b91bea31c"
/>
theguardian.com:
<img width="1624" height="1056" alt="Screenshot 2025-07-27 at 20 33 29"
src="https://github.com/user-attachments/assets/e85daaa6-5fb0-45d4-b9ec-b22b38b087ec"
/>
---------
Signed-off-by: Nico Burns <nico@nicoburns.com>
It was very easy to forget about using `.with_specific_layout_info()` to
set the specific layout info, so it's better to make it a parameter.
In fact this already happened in the past: #36993 fixed the missing
specific layout info for flex items.
This patch fixes it for floats and atomic inlines. It also propagates it
in other cases where not doing so was not a big deal because the
specific layout info was None, but that was a fragile assumption.
Testing: Various WPT improvements
Fixes: #37898
Signed-off-by: Oriol Brufau <obrufau@igalia.com>
Adds support for min-content, max-content, fit-content and stretch,
for block-level elements that don't establish an independent formatting
context, and for block-level elements when there is no float.
Signed-off-by: Oriol Brufau <obrufau@igalia.com>
