The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/cae06e2aab96be77610c27f4a1469f9570df1c3c

commit cae06e2aab96be77610c27f4a1469f9570df1c3c
Author: tbarzic <tbarzic@chromium.org>
Date: Tue Jan 17 23:14:47 2017

Simplify logic behind chrome.audio.setActiveDevices

Main updates:
* Explicitly separates input and output device lists,
which makes setting only one set of devices more intuitive.
This is achieved by introducing DeviceIdLists object that
can be used as method argument.
* Provides a way to clear active devices - by setting
active device lists to an empty list. Old setActiveDevices
method would not change set of active input/output devices if no
input/output devices were added to the list of active device IDs.

Note that the old logic is preserved not to break current clients
but will eventually be removed. Old logic can be triggered by passing
list of device IDs as array of strings rather than a newly introduced
|DeviceIdLists| object.

The CL adds new public methods to CrasAudioHandler to support new way
of setting active devices: SetActiveInputNodes and
SetActiveOutputNodes. These methods are tested by replicating test
cases for ChangeActiveNodes - replacing calls To ChangeActiveNodes with
new methods.

BUG= 680361 

Review-Url: https://codereview.chromium.org/2605983002
Cr-Commit-Position: refs/heads/master@{#444178}

[modify] https://crrev.com/cae06e2aab96be77610c27f4a1469f9570df1c3c/chromeos/audio/cras_audio_handler.cc
[modify] https://crrev.com/cae06e2aab96be77610c27f4a1469f9570df1c3c/chromeos/audio/cras_audio_handler.h
[modify] https://crrev.com/cae06e2aab96be77610c27f4a1469f9570df1c3c/chromeos/audio/cras_audio_handler_unittest.cc
[modify] https://crrev.com/cae06e2aab96be77610c27f4a1469f9570df1c3c/extensions/browser/api/audio/audio_api.cc
[modify] https://crrev.com/cae06e2aab96be77610c27f4a1469f9570df1c3c/extensions/browser/api/audio/audio_service.cc
[modify] https://crrev.com/cae06e2aab96be77610c27f4a1469f9570df1c3c/extensions/browser/api/audio/audio_service.h
[modify] https://crrev.com/cae06e2aab96be77610c27f4a1469f9570df1c3c/extensions/browser/api/audio/audio_service_chromeos.cc
[modify] https://crrev.com/cae06e2aab96be77610c27f4a1469f9570df1c3c/extensions/common/api/audio.idl
[modify] https://crrev.com/cae06e2aab96be77610c27f4a1469f9570df1c3c/extensions/test/data/api_test/audio/test.js