Previously, it would create a new object. The leaves the old
`replaces_id` logic mostly intact for now to keep the full backward
compatibility. I don't think anybody would have noticed the changed, by
time and time again we had proof that some silent users have some
amazing and advanced code hidden somewhere. It could be cleaned later
when breaking compatibility isn't an issue.
The current API is non-compliant with the 1.0 spec and cannot represent
the v1.2 spec at all. The pair of name and callback fails to represent
the explicit ordering and cannot support the icons cleanly.
Plus to support the keyboard navigation use case, the notification
action need to be able to get some sort of focus state. Having an
object makes this easy.
Emmanuel Lepage Vallee