This excludes `step-end` and `step-start` which are expected to be
converted to the equivalent function at parse time.
We are expected to serialize these as the explicit keywords - previously
we would parse as `EasingStyleValue` and serialize equivalent functions
as the keywords. This caused issues as we would incorrectly serialize
even explicit functions as the keyword.
This also allows us to move the magic easing functions to
`EasingFunction` rather than `EasingStyleValue` which is a bit tidier
This reverts 0e3487b9ab.
Back when I made that change, I thought we could make our StyleValue
classes match the typed-om definitions directly. However, they have
different requirements. Typed-om types need to be mutable and GCed,
whereas StyleValues are immutable and ideally wouldn't require a JS VM.
While I was already making such a cataclysmic change, I've moved it into
the StyleValues directory, because it *not* being there has bothered me
for a long time. 😅
This fixes an issue where only the last KeyframeEffect applied to an
element would actually have an effect on the computed properties.
It was particularly noticeable when animating a shorthand property like
border-width, since only one of the border edges would have its width
actually animate.
By deferring the invalidation until all animations have been processed,
we also reduce the amount of work that gets done on pages with many
animations/transitions per element. Discord is very fond of this for
example.
Resulting in a massive rename across almost everywhere! Alongside the
namespace change, we now have the following names:
* JS::NonnullGCPtr -> GC::Ref
* JS::GCPtr -> GC::Ptr
* JS::HeapFunction -> GC::Function
* JS::CellImpl -> GC::Cell
* JS::Handle -> GC::Root
