MouseEvent.offset{X,Y}: not actually experimental

[nfreeze]

MDN URL: https://developer.mozilla.org/en-US/docs/Web/API/MouseEvent/offsetX

What information was incorrect, unhelpful, or incomplete?

I believe listing offsetX and offsetY as experimental is inaccurate considering that they have been supported in every major browser for several years.

Specific section or headline?

Experimental: This is an experimental technology

What did you expect to see?

No warning about it being experimental

Did you test this? If so, how?

Yes. I referenced MDN's definition which deems a feature no longer experimental if it is supported in two or more major browsers.

MDN Content page report details

• Folder: en-us/web/api/mouseevent/offsetx
• MDN URL: https://developer.mozilla.org/en-US/docs/Web/API/MouseEvent/offsetX
• GitHub URL: https://github.com/mdn/content/blob/main/files/en-us/web/api/mouseevent/offsetx/index.md
• Last commit: 2279e5a
• Document last modified: 2021-09-14T18:08:09.000Z

[hamishwillee]

@ddbeck MDN here just reflects BCD. Any particular reason not to modify this in both places?

[Timmmm]

I found this weird too so I've made a PR to fix it. They're definitely not experimental.

[hamishwillee]

Done in #10220. This a slightly bigger change, and I'll have to go do a little more BCD work too.