GitLab

Rename AdapterClient to AdapterObserver to reflect its behavior: as an
observer of Bluetooth changes. Also switch from a single Remote pattern
to a ReceiverSet, allowing Adapter to notify own and notify multiple
AdapterObservers.

This is necessary for future Nearby Connections use, where both
BleMedium and BluetoothClassicMedium will listen on a single
injected Adapter -- see subsequent CL crrev.com/c/2370094.

Bug: b:157748957
Change-Id: If241b76f1662614b1f6061d93b9293e703b58691
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2311824Reviewed-by: Reilly Grant <reillyg@chromium.org>
Reviewed-by: Kyle Horimoto <khorimoto@chromium.org>
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Commit-Queue: Ryan Hansberry <hansberry@chromium.org>
Cr-Commit-Position: refs/heads/master@{#801608}