Improve performance
This patch improves the performance of by replacing the
SynchronousMutationObserver with the existing async MutationObserver in
HTMLOptionElement.
The change from sync to async impacts some tests. The timing is being
discussed in a standards issue here:
whatwg/html#10520
Fixed: 336844298
Change-Id: I9693de9cf35913e7daaebb364c4923dcd4a2dc39
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5758741
Reviewed-by: Mason Freed masonf@chromium.org
Commit-Queue: Joey Arhar jarhar@chromium.org
Cr-Commit-Position: refs/heads/main@{#1337462}