When starting transitions we compute the after-change style, for any
inherited properties this should include the non-animated value.
Previously we were only inheriting the animated value and treating it as
non-animated so were instead including the animated value.
This commit fixes that by inheriting both the animated and non-animated
values (with the former being stored in `m_animated_property_values`,
and the latter in `m_property_values`).
This gains us 12 new WPT passes.
This brings with it 252 new WPT fails from the various 'events' tests in
css/css-transitions/properties-value-inherit-001.html, however these
also fail in other browsers (Chrome, Edge and Firefox) and the behaviour
that causes these failures is specifically mentioned in the spec.
This commit updates the CSSTransition constructor to:
- Leave the KeyframeEffect start time unresolved
- Set the KeyframeEffect start delay
Gains us 14 WPT passes but exposes one false positive in
properties-value-inherit-001.html
If a property is uses discrete interpolation and TransitionBehavior is
not set to `AllowDiscrete` that property should be non-transitionable.
This is now true for properties whose animation type is not discrete,
but the animation type falls back to discrete.
Previously, when serializing a time value, we would always convert it
to seconds. We now canonicalize the time value only when serializing
its computed value.