- The ResizeObserver callback measured the panel and resized the node
synchronously, which forces a layout while the stylesheet may still be
applying; WebKit then reports "ResizeObserver loop completed with
undelivered notifications" as a page error, and the browser fixture
fails any test with a page error (CI WebKit job on PR #108).
- The callback now only schedules a single-flight requestAnimationFrame
that measures and refits, so no observed box changes during delivery.
- Reproduced in the pinned Playwright WebKit image: the picker tests pass
48/48 (16 tests × 3) with this change.
Vito Sansevero
f04f2584a8