This improves the output of `getComputedStyle()` for the `top`,
`bottom`, `left` and `right` properties, where the used value is now
returned rather than the computed value, where applicable."
CSS Values 5 now defines a `<boolean-expr[]>` type that is used in place
of the bespoke grammar that previously existed for `@media` and
`@supports` queries. This commit implements some BooleanExpression
types to represent the nodes in a `<boolean-expr[]>`, and reimplements
`@media` and `@supports` queries using this.
The one part of this implementation I'm not convinced on is that the
`evaluate()` methods take a `HTML::Window*`. This is a compromise
because `@media` requires a Window, and `@supports` does not require
anything at all. As more users of `<boolean-expr[]>` get implemented in
the future, it will become clear if this is sufficient, or if we need
to do something smarter.
As a bonus, this actually improves our serialization of media queries!
Without this, getting a property's value from `element.style.foo` would
fail if `foo` is a shorthand property which has a longhand that is also
a shorthand. For example, `border` expands to `border-width` which
expands to `border-top-width`.
This is because we used `property()` to get a longhand's value, but this
returns nothing if the property is a shorthand.
This commit solves that by moving most of get_property_value() into a
separate method that returns a StyleProperty instead of a String, and
which calls itself recursively for shorthands. Also move the manual
shorthand construction out of ResolvedCSSStyleDeclaration so that all
CSSStyleDeclarations can use it.
This allows us to disable test output, which performs expensive assert
tracking. This was making our imported tests run significantly slower
than tests run via `WPT.sh`.
Formatting the output ourselves also allows us to remove unnecessary
information from the test output.
This commit also rebaselines all existing imported WPT tests to follow
the new format.
Regardless of what the shorthand property is, if all its longhands are
the same CSS-wide keyword such as "initial" or "inherit", then it's the
same as the shorthand being that value.
This gets us 2 WPT subtest passes.
