feat: add aria-checked support to gridcell and row

[smhigley]

🚀 Netlify Preview:
🔄 this PR updates the following sspecs:

• ARIA preview — ARIA diff

Closes #1960

Adds aria-checked as a supported state to gridcell, with the same wording around combining aria-checked & aria-selected as on option and treeitem. The aria-checked support also inherits into columnheader and rowheader.

Test, Documentation and Implementation tracking

Once this PR has been reviewed and has consensus from the working group, tests should be written and issues should be opened on browsers. Add N/A and check when not applicable.

• "author MUST" tests: N/A
• "user agent MUST" tests: Add tentative tests for aria-checked on both gridcell and row roles web-platform-tests/wpt#60504
• Browser implementations (link to issue or commit):
  • WebKit:
  • Gecko: https://bugzilla.mozilla.org/show_bug.cgi?id=2044549
  • Blink:
• Does this need AT implementations? Likely not, since this should come from browser mappings
• Related APG Issue/PR: N/A
• MDN Issue/PR:

---

Preview | Diff

[netlify]

✅ Deploy Preview for wai-aria ready!

Name	Link
🔨 Latest commit	fcede88
🔍 Latest deploy log	https://app.netlify.com/projects/wai-aria/deploys/69d759c502e6fd00084e83d5
😎 Deploy Preview	https://deploy-preview-2390--wai-aria.netlify.app
📱 Preview on mobile	Toggle QR Code... Use your smartphone camera to open QR code link.

---

To edit notification comments on pull requests, go to your Netlify project configuration.

[adampage]

Is there a persuasive and easy-to-describe use case where all of those extremely rare conditions are sufficiently satisfied? 😅 If so, how about offering it in a note?

Otherwise, this LGTM! 🚀

[smhigley]

Is there a persuasive and easy-to-describe use case where all of those extremely rare conditions are sufficiently satisfied? 😅 If so, how about offering it in a note?

Heh, my personal opinion is still that aria-checked and aria-selected never belong on the same node together. That debate happened a while ago though, and the current wording (borrowed from option and treeitem) is the result 🤪

[hidde]

This looks good to me!

[jnurthen]

@mcking65 can you please review

[pkra]

@smhigley rebased on main. I hope I didn't do any damage.

[front-endian]

Looks good to me; really clear and easy to understand!

(Despite having seen some complex tables where this could be used, I really hope people respect the "extremely rare" part of this. 😅)

[spectranaut]

Needs bugs on browsers.

[github-actions]

🚀 Deployed on https://deploy-preview-2390--wai-aria.netlify.app

[HaTheo]

Issue filed for Mozilla: https://bugzilla.mozilla.org/show_bug.cgi?id=2044549