Add missing ARIA attr/prop reflections

[nolanlawson]

Looking at the ARIAMixin spec and the aria* props available on Element.prototype in Chrome, there are a few we're missing.

Missing per Chrome:

• ariaBrailleLabel
• ariaBrailleRoleDescription
• ariaDescription

Missing per the latest spec:

• ariaColIndexText
• ariaDescription
• ariaRowIndexText

Once #3666 is released and we are out of the business of applying global polyfills, it should be safe to add these to the LightningElement/BaseBridgeElement prototypes. This will make it so that a template like:

<x-cmp aria-description="foo"></x-cmp>

...results in the ariaDescription prop (not attr) being set on x-cmp. This is consistent with what we currently do for most ARIA props, which allows for things like overriding the aria* getter/setter, plus convenience accessors like this.aria*.

Note: per Safari we are also missing the *Element/*Elements APIs, but since these are element reflection and not string reflection, we probably shouldn't do anything with these. Also we already have our non-standard string reflection for these:

• ariaActiveDescendantElement
• ariaControlsElements
• ariaDescribedByElements
• ariaDetailsElements
• ariaErrorMessageElements
• ariaFlowToElements
• ariaLabelledByElements
• ariaOwnsElements

[MamataLV]

Hi @nolanlawson,
Is this issue open to fix? And can I work on this?

[nolanlawson]

@MamataLV Yes, but note some uncertainties: #3702 (comment)

[nolanlawson]

Firefox is shipping ARIA string reflection in Nightly. I just checked, and here are the props they support that we don't:

• ariaColIndexText
• ariaDescription
• ariaRowIndexText

This matches the missing props from the spec.

[nolanlawson]

Fixed by #3702