This adds support for table rows, columns, rowgroups and colgroups.
There are few additions here:
1. The createion of fragments, which allows script queries and hit
testing to work properly. These fragments are empty as all cells are
still direct descendants of the table fragment.
2. Properly handling size information from tracks and track groups as
well as frustrating rules about reordering rowgroups.
3. Painting a background seemlessly across track groups and groups. This
is a thing that isn't done in legacy layout (nor WebKit)!
Co-authored-by: Oriol Brufau <obrufau@igalia.com>
The new strategy for dependencies with upstream in Gecko is to manage
them in separate repositories, which will more easily allow rebasing our
changes on top of newer Gecko work.
* Add initial support for sticky positioning for non-legacy layout
Many tests still fail for a variety of reasons. One of the primary ones
is that CSSOM currently does not return correct values for elements
positioned by sticky nodes. This requires changes to WebRender to work
properly.
* Fix an assertion failure in the legacy layout sticky code
This is the start of the organization of types that are in their own
crates in order to break dependency cycles between other crates. The
idea here is that putting these packages into their own directory is the
first step toward cleaning them up. They have grown organically and it
is difficult to explain to new folks where to put new shared types. Many
of these crates contain more than traits or don't contain traits at all.
Notably, `script_traits` isn't touched because it is vendored from
Gecko. Eventually this will move to `third_party`.
