Implement selectedoptionelement attribute
This was resolved here: openui/open-ui#1063
Change-Id: Ie7f464b8cbacbe9614a2e7d34ccf1805a93f3bbd
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5763175
Commit-Queue: Joey Arhar jarhar@chromium.org
Reviewed-by: Mason Freed masonf@chromium.org
Cr-Commit-Position: refs/heads/main@{#1339783}