Need a decision on what the computedrole should return on extension specs

[cookiecrook]

In order to move forward with testing computed roles the DPUB-ARIA and Graphics-ARIA (+SVG-ARIA) extension specifications as part of the Interop 2023 Accessibility Investigation, the ARIA WG needs to make a decision on what the computedrole should return on extension specs.

Currently it is unspecified, so there is no "correct" value.

1. literal role name from the extension spec (current Chromium behavior)... e.g. graphics-document
2. aria superclass role name (current WebKit behavior)… e.g. document
3. leave it unspecified with explicit statement that either is ok (likely unprecedented for "interop" tests)
4. default specified in ARIA, but allows override in extension on a per-spec basis?
5. something else?

More info and Draft PR here:
web-platform-tests/interop-accessibility#9 (comment)

[cookiecrook]

@benbeaudry suggested I assign @aleventhal to get his opinion on this and related:

• graphics-aria role mappings needed as precursor to svg-aam role mappings web-platform-tests/interop-accessibility#9 (comment)

[cookiecrook]

• Add computedrole column for HTML-AAM html-aam#464
• Define computedrole for graphics-* roles graphics-aam#7
• Define computedrole for the SVG roles table svg-aam#24
• Define computedrole for doc-* roles dpub-aam#29

Did I miss any?