GitLab

Use the existing PeripheralBatteryNotifier to show low battery
notifications of connected device::BluetoothDevice objects. This CL
adds functionality to trigger for GATT connections that support the
Battery Service.

Also added DeviceBatteryChanged() to device::BluetoothAdapter::Observer
so device::BluetoothDevice can notify about battery level changes and
PeripheralBatteryNotifier gets notified about those changes.

Also modified BluetoothDevice to make the battery percentage property
OS_CHROMEOS-only.

Design doc at go/cros-bt-battery.

Bug: 785758
Change-Id: I325e6bf47032fe5fc2a7471d2a1be9850fd89030
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1703341
Commit-Queue: Alberto Herrera <ahrfgb@google.com>
Reviewed-by: James Cook <jamescook@chromium.org>
Reviewed-by: Reilly Grant <reillyg@chromium.org>
Reviewed-by: Ryan Hansberry <hansberry@chromium.org>
Reviewed-by: Kyle Horimoto <khorimoto@chromium.org>
Cr-Commit-Position: refs/heads/master@{#682791}