commit 027aefc6b58096d2aba33def4e882d61b5c70c1f
author Kent Tamura <tkent@chromium.org> Tue Jun 09 08:53:00 2020
committer Commit Bot <commit-bot@chromium.org> Tue Jun 09 08:53:00 2020
tree e21936d006bfbd3cefc8bc34e45aaa5704ba471f
parent 5e30de3b2eedca818352696956e815c466fa61b3

OPTION element: Update OPTION label even if it has invalid markup

https://html.spec.whatwg.org/C/#the-option-element
> Content model:
> If the element has no label attribute and is not a child of a datalist
> element: Text that is not inter-element whitespace.

OPTION elements should not have element children, but they can have if
web authors add elements by DOM API.

For both of drop-down SELECTs and listbox SELECTs, Chrome missed to
update OPTION labels. It's a regression since Google Chrome 83 for
drop-down SELECT, and the issue exists since the WebKit fork for
listbox SELECTs.

This CL fixes the issue by using MutationObserver only if an OPTION
element has Element children.

Bug: 1090806
Change-Id: I69f5aa4646fda0ad2770cc2748016c6b37b3ad06
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2235227
Commit-Queue: Kent Tamura <tkent@chromium.org>
Reviewed-by: Yoshifumi Inoue <yosin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#776436}