Bug 1878797 [wpt PR 44408] - Close the dialog element when the open a…

…ttribute is removed, a=testonly

Automatic update from web-platform-tests
Close the dialog element when the open attribute is removed

This patch adds HTMLDialogElement::ParseAttribute which runs
HTMLDialogElement::close when the open attribute is removed to prevent a
bad state where the dialog is modal but hidden and inerting the rest of
the document.

Spec discussion is happening here:
whatwg/html#5802

Change-Id: Ib90736ced952d7aeadc791c6863c3ac2a55deb62
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5269905
Reviewed-by: David Baron <dbaronchromium.org>
Commit-Queue: Joey Arhar <jarharchromium.org>
Cr-Commit-Position: refs/heads/main{#1258629}

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wpt-commits: c0538d5500ef425b051f7dcb37772af5025324d0
wpt-pr: 44408

UltraBlame original commit: 1ad3db0d81f20d2319adf0d009fabe2d4b1b8ca0