A list from looking at content/browser & devices:
battery_status, bluetooth, device_sensors, gamepad, geolocation, nfc, power_save_blocker, serial, screen_orientation, time_zone_monitor, usb, vibration, vr, wake_lock

I'm working on this effort. Taking the bug simply to signify that someone is actively working on this from an end-to-end POV, but of course more than happy to coordinate with anyone else who is working or wants to work on it.

Hi, blundell@, I'd like to take part in this work as your assistant. I've done some mojofication work and I think I'll also be proved helpful here. ;-)
# After reading codes/docs inside //services/, //content/browser/mojo/ and content/common/mojo/, I've got some knowledge about Service/Shell etc. and how they're deployed in Chrome. I understand we want to create a new device Service here.

Maybe I could start with mojofying some device piece still using legacy IPC, or whatever work following your plan. Thanks~

Great! Communicated with you offline to start to determine work breakdown.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/372d47d28a581be1a9baec3505b805d982129e37

commit 372d47d28a581be1a9baec3505b805d982129e37
Author: blundell <blundell@chromium.org>
Date: Tue Nov 01 01:34:30 2016

Introduce Device Service

This CL introduces the Device Service into //services/device along
with the infrastructure required in //content for the renderer to
connect to it and the browser to host it as an embedded service.

The service is currently empty. A followup CL will move the first
device-related service to be host in the Device Service instead of in
//content/browser.

BUG=612328

Review-Url: https://codereview.chromium.org/2451413003
Cr-Commit-Position: refs/heads/master@{#428904}

[modify] https://crrev.com/372d47d28a581be1a9baec3505b805d982129e37/content/browser/BUILD.gn
[modify] https://crrev.com/372d47d28a581be1a9baec3505b805d982129e37/content/browser/browser_context.cc
[modify] https://crrev.com/372d47d28a581be1a9baec3505b805d982129e37/content/public/app/BUILD.gn
[add] https://crrev.com/372d47d28a581be1a9baec3505b805d982129e37/services/device/BUILD.gn
[add] https://crrev.com/372d47d28a581be1a9baec3505b805d982129e37/services/device/OWNERS
[add] https://crrev.com/372d47d28a581be1a9baec3505b805d982129e37/services/device/device_service.cc
[add] https://crrev.com/372d47d28a581be1a9baec3505b805d982129e37/services/device/device_service.h
[add] https://crrev.com/372d47d28a581be1a9baec3505b805d982129e37/services/device/manifest.json
[add] https://crrev.com/372d47d28a581be1a9baec3505b805d982129e37/services/device/public/cpp/BUILD.gn
[add] https://crrev.com/372d47d28a581be1a9baec3505b805d982129e37/services/device/public/cpp/constants.cc
[add] https://crrev.com/372d47d28a581be1a9baec3505b805d982129e37/services/device/public/cpp/constants.h

Migrating S13N meta bugs to Type=Task, so that they can be distinguished from technical work.