The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/06fd861c6a9b1febfcd71860ca1993b62801a0ae

commit 06fd861c6a9b1febfcd71860ca1993b62801a0ae
Author: Balazs Engedy <engedy@chromium.org>
Date: Tue Jan 09 10:29:38 2018

Notify observers when U2F service is discovered on existing BLE device.

U2fDiscovery::Observer::DeviceAdded should also be invoked when the U2F
service is discovered on a pre-existing BLE device that was not
previously known to implement the service (e.g. because the service
advertisements were lost or not cached).

Bug:  799987 
Change-Id: Id1f65383a4b624740e2e0068ac0ecdc5dafcec74
Reviewed-on: https://chromium-review.googlesource.com/854278
Commit-Queue: Balazs Engedy <engedy@chromium.org>
Reviewed-by: Jan Wilken Dörrie <jdoerrie@chromium.org>
Reviewed-by: Reilly Grant <reillyg@chromium.org>
Cr-Commit-Position: refs/heads/master@{#527954}
[modify] https://crrev.com/06fd861c6a9b1febfcd71860ca1993b62801a0ae/device/bluetooth/dbus/fake_bluetooth_device_client.cc
[modify] https://crrev.com/06fd861c6a9b1febfcd71860ca1993b62801a0ae/device/bluetooth/dbus/fake_bluetooth_device_client.h
[modify] https://crrev.com/06fd861c6a9b1febfcd71860ca1993b62801a0ae/device/bluetooth/test/bluetooth_test_bluez.cc
[modify] https://crrev.com/06fd861c6a9b1febfcd71860ca1993b62801a0ae/device/u2f/u2f_ble_discovery.cc
[modify] https://crrev.com/06fd861c6a9b1febfcd71860ca1993b62801a0ae/device/u2f/u2f_ble_discovery.h
[modify] https://crrev.com/06fd861c6a9b1febfcd71860ca1993b62801a0ae/device/u2f/u2f_ble_discovery_unittest.cc