Reason for revert:
This was false alarm. The next Chromium roll fixed the problem and the bot has been green for 3 builds.
Original issue's description:
> Disabled two iOS tests due to bot breakage. Affected tests are
> AudioDeviceTest.RunPlayoutWithFileAsSource and
> AudioDeviceTest.StartStopRecording
>
> NOTRY=True
> TBR=henrika@webrtc.org
> BUG=7056
>
> Review-Url: https://codereview.webrtc.org/2652423002
> Cr-Commit-Position: refs/heads/master@{#16286}
> Committed: 8e775e16eb
TBR=henrika@webrtc.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=7056
Review-Url: https://codereview.webrtc.org/2656533005
Cr-Commit-Position: refs/heads/master@{#16289}