Intent to prototype and ship: ARIA annotations

[James Teh]

In Firefox 75, we intend to enable ARIA annotations by default.

Summary: This adds two new ARIA roles, a new aria-description attribute and
expands aria-details. These changes are needed to support screen reader
accessibility of comments, suggestions and other annotations in published
documents and online word processing scenarios such as Google Docs, iCloud
Pages, and MS Office Online. This is not currently possible without
resorting to live region hacks, which are not as reliable as semantics and
do not work well with Braille displays. As a result, screen reader users
have non-optimal support for collaboration features of online word
processors.
Bug: https://bugzilla.mozilla.org/show_bug.cgi?id=1608975
Standard: Incorporated into ARIA 1.3 editor's draft. Explainer with links
to pull requests: https://github.com/aleventhal/aria-annotations
Platform coverage: desktop
Preference: None. Because this simply exposes new values to accessibility
clients using existing accessibility APIs, we do not anticipate any
problems.
DevTools bug: None. Both the DOM inspector and accessibility inspector will
reflect this new information without any additional work.
Other browsers: Chrome shipping enabled by default in version 82:
https://chromestatus.com/feature/4666935918723072
web-platform-tests: None. ARIA WPT is still somewhat of a work in progress
and hasn't been updated for ARIA 1.2 yet, let alone 1.3. We will have Gecko
tests, though.
Secure contexts: Not restricted to secure contexts, consistent with the
rest of ARIA.
Is this feature enabled by default in sandboxed iframes?: Yes; has no
impact on sandboxed iframes.
Link to standards-positions discussion:
https://github.com/mozilla/standards-positions/issues/253
How stable is the spec: The spec is straightforward and has been reviewed
and approved by stakeholders across the accessibility industry. We do not
anticipate any fundamental changes.

Jamie