Avoids error message about unknown selected data source for Port iPhone Microphone

Avoids error message about unknown selected data source for Port iPhone Microphone

TBR=tkchin
BUG=webrtc:4845
TEST=modules_unittests

Committed: https://chromium.googlesource.com/external/webrtc/+/324d9c9a86e2fa331234eb0fa227845fde9f0317

[henrika_webrtc, 2015-07-17 10:50:41]

henrika@webrtc.org changed reviewers:
+ tkchin@webrtc.org

[henrika_webrtc, 2015-07-17 10:56:07]

Fixing an issue that was added by me in my previous CL where I deactivated the
audio session too early.
The audio session is now only ended at termination (or when all media streaming
has stopped). 
The error message mentioned in the title was just one visible symptom of the
deactivated audio session
but I guess that there we several hidden issues as well.

A more suitable title could be: "Keeping the audio session active while audio
streaming is active"

[henrika_webrtc, 2015-07-17 10:58:44]

tkchin@ please check this CL.

https://codereview.webrtc.org/1237233003/diff/40001/webrtc/modules/audio_devi...
File webrtc/modules/audio_device/ios/audio_device_ios.mm (left):

https://codereview.webrtc.org/1237233003/diff/40001/webrtc/modules/audio_devi...
webrtc/modules/audio_device/ios/audio_device_ios.mm:669: // Deactivate the audio
session.
This is wrong and can cause many issues (e.g. the error message given in the
title).
It is too early to end the audio session here!

[henrika_webrtc, 2015-07-20 11:08:45]

Landing with tkchin@ as TBR since this is such a fundamental issue where we
currently run all
iOS audio with an explicitly disabled audio session.

[henrika_webrtc, 2015-07-20 11:08:58]

The CQ bit was checked by henrika@webrtc.org

[commit-bot: I haz the power, 2015-07-20 11:09:07]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1237233003/60001

[henrika_webrtc, 2015-07-20 11:09:13]

The CQ bit was unchecked by henrika@webrtc.org

[henrika_webrtc, 2015-07-20 11:09:42]

Committed patchset #4 (id:60001) manually as
324d9c9a86e2fa331234eb0fa227845fde9f0317 (presubmit successful).