This reverts commit 0e96535be9.
Reason for revert: Downstream test failure
Original change's description:
> Inlines NullAudioPoller functionality into AudioState class.
>
> As part of this, we also use TaskQueue and RepeatedTask rather
> than rtc::Thread + rtc::MessageHandler. With the ultimate goal of
> deprecating rtc::Thread.
>
> Bug: webrtc:9883
> Change-Id: I2fb851ac31ee2431435d51de78ff446572512201
> Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/167528
> Commit-Queue: Sebastian Jansson <srte@webrtc.org>
> Reviewed-by: Sam Zackrisson <saza@webrtc.org>
> Cr-Commit-Position: refs/heads/master@{#30430}
TBR=saza@webrtc.org,srte@webrtc.org
Change-Id: I4c77259f7b6477fc1cb79350f2d47817f106770d
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: webrtc:9883
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/168046
Reviewed-by: Sebastian Jansson <srte@webrtc.org>
Commit-Queue: Sebastian Jansson <srte@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#30431}
fdbbada4d1