Made WebRTC AQ test two-way, adjusted volume on Mac.

Made WebRTC AQ test two-way, adjusted volume on Mac.

It turns out automated echo cancellation only gets enabled for two-way
calls. Since we want to test the complex AEC in WebRTC (and the other
audio processing for that matter), we must make the test call two-way
rather than one-way as it used to be for simplicity. With these
changes, we should be able to catch bugs like 453907 on the desktop
platforms.

Note: should land together with https://codereview.chromium.org/922663002/.

BUG=453907
Committed: https://crrev.com/7ece40694beef0b342a776506040254f7110eb40
Cr-Commit-Position: refs/heads/master@{#317560}

[phoglund_chromium, 2015-02-17 13:19:59]

phoglund@chromium.org changed reviewers:
+ henrika@chromium.org

[henrika (OOO until Aug 14), 2015-02-17 13:36:13]

LGTM

[phoglund_chromium, 2015-02-20 14:23:39]

New patchsets have been uploaded after l-g-t-m from henrika@chromium.org

[phoglund_chromium, 2015-02-20 14:24:09]

I forgot to actually re-enable the test on mac, so I uploaded a patch set that
does that.

[phoglund_chromium, 2015-02-23 10:26:31]

The CQ bit was checked by phoglund@chromium.org

[commit-bot: I haz the power, 2015-02-23 10:27:29]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/934793002/20001

[commit-bot: I haz the power, 2015-02-23 10:30:19]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-02-23 10:31:00]

Patchset 2 (id:??) landed as
https://crrev.com/7ece40694beef0b342a776506040254f7110eb40
Cr-Commit-Position: refs/heads/master@{#317560}