On Nov 16, 2018, at 10:44 AM, Ryosuke Niwa <rniwa@webkit.org> wrote:

If a stub implementation is ok for ports without an actual accessibility implementation then I’d say remove both flags. Then downstream users would never have to worry about breaking due to AX signatures changing.

I don't think a stub implementation is okay.

Removing ENABLE(ACCESSIBILITY) would be fine. Either way, I do think we need a better way to maintain !HAVE(ACCESSIBILITY).

There have been at least ~38 build fixes for !HAVE(ACCESSIBILITY) over the years — one every 2-3 months on average. It was one of the pain points I remember in maintaining an outside port.

https://trac.webkit.org/search?q=%21HAVE%28ACCESSIBILITY%29

— Timothy Hatcher