In the next few patches we move all non-transition related code over to
using AnimatableLonghand instead of TransitionProperty. This will allow
us to re-purpose TransitionProperty to represent only properties that
can be transitioned (i.e. excluding discrete properties) as well as
simplifying the code by removing the need to deal with shorthands and
the "all" value in places that do not need to handle those values.
I saw this function appear in the profiles at #17329.
It was under set_device, which isn't a Stylo path, but probably worth there
anyway.
This reduces the reported overhead of RulesIterator::next in perf from ~8% to
0.46%
This file has become quite bloated lately. This commit deletes that file in
favor of a set of submodules.
The only noticeable change apart from code move, is converting deep_clone_foo
methods into a trait.
It also unifies logic related to different style rules in the same place.
There's some missing work, specially related to font-face and counter-style, but
I think this is worth landing in the meantime.
