
The callback can be held in ExternalCanvasResource provider that can be used on main thread and worker thread in case of offscreen canvas with placeholder. While the callback will never run on the wrong thread, we can't guarantee that it won't be destroyed on a wrong thread, because the worker thread that owns it could be destroyed by javascript. Bug: 352263194 Change-Id: I8af66aea9ed1e70dd7e832772fdd4a1bce6ed70f Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6513314 Reviewed-by: Colin Blundell <blundell@chromium.org> Commit-Queue: Vasiliy Telezhnikov <vasilyt@chromium.org> Cr-Commit-Position: refs/heads/main@{#1457132}