Marking Chips as buttons helps accessibility tools,
search engines, and other semantic analysis software
understand the meaning of an app. For example, it
allows screen readers (such as TalkBack on Android
and VoiceOver on iOS) to announce a tappable Chip
as a “button”, which can assist users in navigating
your app. Prior to this change, users of accessibility
tools may have had a subpar experience,
unless you implemented a workaround by manually adding the
missing semantics to the Chip widgets in your app.

Description of change

The outermost Semantics widget that wraps all
Chip classes to describe their semantic properties
is modified.

The following changes apply to
ActionChip, ChoiceChip, FilterChip,
and InputChip:

The button property
is set to true.

The enabled property
reflects whether the Chip is currently tappable
(by having a callback set).