The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/178de915df8930825191e6929c0d9211dd2ff816

commit 178de915df8930825191e6929c0d9211dd2ff816
Author: Kyle Horimoto <khorimoto@google.com>
Date: Wed Jul 19 20:20:39 2017

[CrOS Tether] Add Bluetooth notification to NotificationPresenter.

This notification is not actually shown by the Tether component yet; this
functionality will be part of a follow-up CL.

Bug: 672263,  740635 
Change-Id: Ic9b40af6a90631fbc0624b39375224e8d2f6221a
Reviewed-on: https://chromium-review.googlesource.com/577063
Commit-Queue: Kyle Horimoto <khorimoto@chromium.org>
Reviewed-by: Steven Bennetts <stevenjb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#487947}
[modify] https://crrev.com/178de915df8930825191e6929c0d9211dd2ff816/chrome/app/chromeos_strings.grdp
[modify] https://crrev.com/178de915df8930825191e6929c0d9211dd2ff816/chrome/browser/chromeos/net/tether_notification_presenter.cc
[modify] https://crrev.com/178de915df8930825191e6929c0d9211dd2ff816/chrome/browser/chromeos/net/tether_notification_presenter.h
[modify] https://crrev.com/178de915df8930825191e6929c0d9211dd2ff816/chrome/browser/chromeos/net/tether_notification_presenter_unittest.cc
[modify] https://crrev.com/178de915df8930825191e6929c0d9211dd2ff816/chromeos/components/tether/fake_notification_presenter.cc
[modify] https://crrev.com/178de915df8930825191e6929c0d9211dd2ff816/chromeos/components/tether/fake_notification_presenter.h
[modify] https://crrev.com/178de915df8930825191e6929c0d9211dd2ff816/chromeos/components/tether/notification_presenter.h

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/1a84bb656091ec0721a800caedd36639aef7db38

commit 1a84bb656091ec0721a800caedd36639aef7db38
Author: Kyle Horimoto <khorimoto@google.com>
Date: Thu Jul 20 23:50:12 2017

[CrOS Tether] Show the "Enable Bluetooth" notification when appropriate.

The notification can be shown during two point in time: when the user logs in,
and when the user disconnects from the Internet. In order for the notification
to be shown, Bluetooth must be disabled, the device must be disconnected from
the Internet, and there must be nothing besides Bluetooth preventing a Tether
scan from beginning.

This CL also changes the ownership of TetherNotificationPresenter. Now, one
instance is created and owned by TetherService and is passed through to the
Tether component when needed. Previously, the instance was owned by the Tether
component, but this no longer worked due to the fact that TetherService needed
to be able to display the "enable Bluetooth" notification when Tether was left
uninitialized (due to Bluetooth being disabled).

Lastly, now TetherService only sets Tether's TechnologyState to
UNINITIALIZED when Bluetooth is disabled, which fixes an issue in which
an "enable Bluetooth" message is shown in Quick Settings when Bluetooth
is on but Cellular is disabled.

Bug: 672263,  740635 
Change-Id: Id19a847a9efb7a31d23d2ffb6308fad7d46ca948
Reviewed-on: https://chromium-review.googlesource.com/580349
Commit-Queue: Kyle Horimoto <khorimoto@chromium.org>
Reviewed-by: Steven Bennetts <stevenjb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#488488}
[modify] https://crrev.com/1a84bb656091ec0721a800caedd36639aef7db38/ash/system/network/network_icon.cc
[modify] https://crrev.com/1a84bb656091ec0721a800caedd36639aef7db38/chrome/browser/chromeos/BUILD.gn
[modify] https://crrev.com/1a84bb656091ec0721a800caedd36639aef7db38/chrome/browser/chromeos/net/tether_notification_presenter.cc
[modify] https://crrev.com/1a84bb656091ec0721a800caedd36639aef7db38/chrome/browser/chromeos/net/tether_notification_presenter.h
[modify] https://crrev.com/1a84bb656091ec0721a800caedd36639aef7db38/chrome/browser/chromeos/tether/tether_service.cc
[modify] https://crrev.com/1a84bb656091ec0721a800caedd36639aef7db38/chrome/browser/chromeos/tether/tether_service.h
[modify] https://crrev.com/1a84bb656091ec0721a800caedd36639aef7db38/chrome/browser/chromeos/tether/tether_service_unittest.cc
[modify] https://crrev.com/1a84bb656091ec0721a800caedd36639aef7db38/chromeos/components/tether/initializer.cc
[modify] https://crrev.com/1a84bb656091ec0721a800caedd36639aef7db38/chromeos/components/tether/initializer.h
[modify] https://crrev.com/1a84bb656091ec0721a800caedd36639aef7db38/chromeos/components/tether/initializer_unittest.cc