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. 😅
A change to a counter "definition" propagates to all subsequent
instances of this counter: descendents, siblings and their descendents
(the "next tree slice"). Rebuilding the layout tree (from the parent
node) covers at least the "next_tree_slice".
When position changes, we may need to make larger structural updates
to the layout tree. A simple relayout is not sufficient.
This was a source of flakiness in the engine, and gives us at least
+28 new WPT subtest passes.
Because we cache the transformed text string in text nodes affected by
text-transform, we have to actually update the layout tree when this
property value changes.
