Disallow "presentation' or 'none' role on an iframe element

[shunguoy]

With the recent update from Chrome, major browsers support automatic focus on an iframe element. The role "presentation" or "none" on an iframe element causes conflict: accessible through keyboard but not through a screen reader, and the resolution to the conflict might be user agent dependent.

[scottaohara]

maybe i can reopen #370 where i was trying to work ahead of changes like this

[shunguoy]

Here are some quick test results: with role='presentation' on an iframe element:
Chrome takes out the iframe content from the accessibility tree
Firefox uses its internal role "internal frame" instead of "presentation", and the iframe content is in the accessibility tree.
Safari: VoiceOver announces the frame's content. The only difference from another frame without a "presentation" role is that the announcement starts with "x items" rather than "in frame x".
The implementations are inconsistent with the ARIA Presentational Roles Conflict Resolution.
@scottaohara

[scottaohara]

this looks similar to some of the issues i was finding when i tried updating this rule previously. using these roles on iframes can break them.

does your issue indicate that if ARIA in HTML were to update to point out these issues and indicate that authors should not be using these roles on iframes, that IBM would be supportive this time around?