BREAKING CHANGE: chips now follow the [aria toolbar pattern](https://www.w3.org/WAI/ARIA/apg/patterns/toolbar/examples/toolbar/). Chip sets are toolbars and chips are buttons or links. Filter chips are toggle buttons.
What to change:
- Remove `type` attribute from `<md-chip-set>` (you can mix and match chip types!)
- Remove `single-select` from `<md-chip-set>`. Use JS to control filter chips if single selection is required. Radio filter chips will come in a future update.
- Disabled chips CAN be focused with the keyboard if `always-focusable` is set.
- Filter chips no longer dispatch a `"selected"` event. Listen to `"click"` and use `event.target.selected` instead.
- ArrowUp and ArrowDown no longer navigate between chips. These are reserved for chip actions, like dropdown menu chips.
PiperOrigin-RevId: 566352830
A lot of the changes are in order to fix filter chips with VoiceOver. With the extra divs and no aria-hidden on ripple/focus ring, VoiceOver got stuck on the first filter chip with linear navigation.
Elevated link chips also got their border changed to white instead of yellow in HCM to match Wiz.
PiperOrigin-RevId: 559908582
