Replace the unsafe HashTable<GC::Weak<Animation>> with
GC::WeakHashSet<Animation>, and update all callers to use reference
syntax instead of pointer syntax since the iterator now yields T&.
An animation with an orphaned owning element should continue to be
ticked by the timeline.
Reverts c8b574e and instead avoids leaking animations by not visiting
`Animation`s from `AnimationTimeline`s.
Fixes a timeout in the imported test
In level 2 of the web animations spec, times are no longer always
measures in milliseconds, they can also be percents when dealing with
progress-based (i.e. scroll-based) timelines.
We don't actually support percent times yet but this change will make it
easier to implement when we do.
This was added in Level 2 of the Web Animations spec
In this level of the spec, all time values associated with animations
(including this duration property) are no longer simple numbers but are
instead either percentages or numbers for progress- and time-based
timelines respectively. These values are represented internally by a new
`TimeValue` wrapper struct, and externally (i.e. in JS) as
`CSSNumberish`.
This method did two things:
1) on the base class (`AnimationTimeline`) it was a setter for
`m_current_time` and;
2) on the child classes (e.g. `DocumentTimeline`) it updated the
timeline's current time given a document timestamp
It makes more sense for theses to be distinct methods
Our previous implementation kept track of an AnimationTimeline being
monotonically increasing, by looking at new time values coming in and
setting `m_monotonically_increasing` to `false` whenever a new value
is before the previous known time value.
As far as I can tell, the spec doesn't really ask us to do so: it just
defines 'monotonically increasing' as a property of a timeline, i.e. it
guarantees that returned time values from `::current_time()` are always
greater than or equal to the last returned value.
This fixes a common crash seen when the last render opportunity lies
before the document's origin time, and `::set_current_time()` was
invoked with a negative value. This was especially visible in the
`Text/input/wpt-import/css/cssom/CSSStyleSheet-constructable.html` test.
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
