Reland: Pass task runners to AudioManager constructor.

Reland: Pass task runners to AudioManager constructor.

This patch replaces the internal AudioManagerBase::audio_thread with
an external task runner. The old implementation made it harder to test
and override the internal audio thread.

AudioManagerBase::Shutdown had to complete on the audio thread before
the AudioManager instance could be deleted. It relied on Thread::Stop
on the main thread to wait for the audio thread to shutdown. A subclass
using a different thread shared with other modules could not do that.

Passing a task runner into AudioManager and making GetTaskRunner
non-virtual ensures that the task runner will not change for the
lifetime of AudioManager instance.

BUG=594234
TBR=rkc,tommi,xhwang,jam,dalecurtis

Committed: https://crrev.com/1f4996786dd7ab2e5d7f51c72f9309ee50aeb176
Cr-Commit-Position: refs/heads/master@{#388211}

[alokp, 2016-04-19 14:07:53]

Description was changed from

==========
Reland: Pass task runners to AudioManager constructor.

This patch replaces the internal AudioManagerBase::audio_thread with
an external task runner. The old implementation made it harder to test
and override the internal audio thread.

AudioManagerBase::Shutdown had to complete on the audio thread before
the AudioManager instance could be deleted. It relied on Thread::Stop
on the main thread to wait for the audio thread to shutdown. A subclass
using a different thread shared with other modules could not do that.

Passing a task runner into AudioManager and making GetTaskRunner
non-virtual ensures that the task runner will not change for the
lifetime of AudioManager instance.

BUG=594234
==========

to

==========
Reland: Pass task runners to AudioManager constructor.

This patch replaces the internal AudioManagerBase::audio_thread with
an external task runner. The old implementation made it harder to test
and override the internal audio thread.

AudioManagerBase::Shutdown had to complete on the audio thread before
the AudioManager instance could be deleted. It relied on Thread::Stop
on the main thread to wait for the audio thread to shutdown. A subclass
using a different thread shared with other modules could not do that.

Passing a task runner into AudioManager and making GetTaskRunner
non-virtual ensures that the task runner will not change for the
lifetime of AudioManager instance.

BUG=594234
TBR=rkc,tommi,xhwang,jam,dalecurtis
==========

[alokp, 2016-04-19 14:08:11]

The CQ bit was checked by alokp@chromium.org

[commit-bot: I haz the power, 2016-04-19 14:08:21]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1894373002/40001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1894373002/40001

[commit-bot: I haz the power, 2016-04-19 15:26:38]

Description was changed from

==========
Reland: Pass task runners to AudioManager constructor.

This patch replaces the internal AudioManagerBase::audio_thread with
an external task runner. The old implementation made it harder to test
and override the internal audio thread.

AudioManagerBase::Shutdown had to complete on the audio thread before
the AudioManager instance could be deleted. It relied on Thread::Stop
on the main thread to wait for the audio thread to shutdown. A subclass
using a different thread shared with other modules could not do that.

Passing a task runner into AudioManager and making GetTaskRunner
non-virtual ensures that the task runner will not change for the
lifetime of AudioManager instance.

BUG=594234
TBR=rkc,tommi,xhwang,jam,dalecurtis
==========

to

==========
Reland: Pass task runners to AudioManager constructor.

This patch replaces the internal AudioManagerBase::audio_thread with
an external task runner. The old implementation made it harder to test
and override the internal audio thread.

AudioManagerBase::Shutdown had to complete on the audio thread before
the AudioManager instance could be deleted. It relied on Thread::Stop
on the main thread to wait for the audio thread to shutdown. A subclass
using a different thread shared with other modules could not do that.

Passing a task runner into AudioManager and making GetTaskRunner
non-virtual ensures that the task runner will not change for the
lifetime of AudioManager instance.

BUG=594234
TBR=rkc,tommi,xhwang,jam,dalecurtis
==========

[commit-bot: I haz the power, 2016-04-19 15:26:39]

Committed patchset #3 (id:40001)

[commit-bot: I haz the power, 2016-04-22 19:12:23]

Description was changed from

==========
Reland: Pass task runners to AudioManager constructor.

This patch replaces the internal AudioManagerBase::audio_thread with
an external task runner. The old implementation made it harder to test
and override the internal audio thread.

AudioManagerBase::Shutdown had to complete on the audio thread before
the AudioManager instance could be deleted. It relied on Thread::Stop
on the main thread to wait for the audio thread to shutdown. A subclass
using a different thread shared with other modules could not do that.

Passing a task runner into AudioManager and making GetTaskRunner
non-virtual ensures that the task runner will not change for the
lifetime of AudioManager instance.

BUG=594234
TBR=rkc,tommi,xhwang,jam,dalecurtis
==========

to

==========
Reland: Pass task runners to AudioManager constructor.

This patch replaces the internal AudioManagerBase::audio_thread with
an external task runner. The old implementation made it harder to test
and override the internal audio thread.

AudioManagerBase::Shutdown had to complete on the audio thread before
the AudioManager instance could be deleted. It relied on Thread::Stop
on the main thread to wait for the audio thread to shutdown. A subclass
using a different thread shared with other modules could not do that.

Passing a task runner into AudioManager and making GetTaskRunner
non-virtual ensures that the task runner will not change for the
lifetime of AudioManager instance.

BUG=594234
TBR=rkc,tommi,xhwang,jam,dalecurtis

Committed: https://crrev.com/1f4996786dd7ab2e5d7f51c72f9309ee50aeb176
Cr-Commit-Position: refs/heads/master@{#388211}
==========

[commit-bot: I haz the power, 2016-04-22 19:12:24]

Patchset 3 (id:??) landed as
https://crrev.com/1f4996786dd7ab2e5d7f51c72f9309ee50aeb176
Cr-Commit-Position: refs/heads/master@{#388211}