This partially reverts commit 3aff3327c4
by removing the code change but keeping the added test.
Now that paintables visibility caching has been reverted, this is no
longer doing anything except causing excessive relayouts on pages
like https://linear.app/
As of 7dc8062 paintables compute and cache their visibility (which
depends on opacity) at construction - this cached value can fall out of
sync with reality if if the opacity changes to/from zero within the
lifetime of that paintable.
This commit invalidates layout when an opacity changes to/from zero so
that we reconstruct paintables with the correct visibility.
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.
