ACM/NetEq: Restructure how post-decode VAD is enabled

ACM/NetEq: Restructure how post-decode VAD is enabled

This change avoids calling neteq_->EnableVad() and DisableVad from the
AcmReceiver constructor. Instead, the new member
enable_post_decode_vad is added to NetEq's config struct. It is
disabled by defualt, but ACM sets it to enabled. This preserves the
behavior both of NetEq stand-alone (i.e., in tests) and of ACM.

BUG=webrtc:3520
Committed: https://crrev.com/9bc2667fa6deee5d4162b13a878481640a58cce5
Cr-Commit-Position: refs/heads/master@{#10476}

[hlundin-webrtc, 2015-10-29 10:55:47]

henrik.lundin@webrtc.org changed reviewers:
+ kwiberg@webrtc.org

[hlundin-webrtc, 2015-10-29 10:55:48]

PTAL

[kwiberg-webrtc, 2015-11-01 11:09:04]

lgtm

[hlundin-webrtc, 2015-11-01 20:44:16]

The CQ bit was checked by henrik.lundin@webrtc.org

[commit-bot: I haz the power, 2015-11-01 20:44:26]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1425133002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1425133002/1

[commit-bot: I haz the power, 2015-11-01 20:57:05]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-11-01 20:57:06]

Try jobs failed on following builders:
  linux_msan on tryserver.webrtc (JOB_FAILED,
http://build.chromium.org/p/tryserver.webrtc/builders/linux_msan/builds/5650)

[hlundin-webrtc, 2015-11-02 10:28:10]

Actually doing something with the new config

[hlundin-webrtc, 2015-11-02 10:28:57]

The CQ bit was checked by henrik.lundin@webrtc.org to run a CQ dry run

[commit-bot: I haz the power, 2015-11-02 10:29:06]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1425133002/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1425133002/20001

[hlundin-webrtc, 2015-11-02 10:31:41]

I managed to forget a rather crucial detail in the first patch set, but the try
bots caught that. Fixed in patch set #2. You may want to take a new look, but I
will commit this if the try jobs are all green.

[kwiberg-webrtc, 2015-11-02 10:59:29]

lgtm

[commit-bot: I haz the power, 2015-11-02 11:20:20]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-11-02 11:20:20]

Dry run: This issue passed the CQ dry run.

[hlundin-webrtc, 2015-11-02 11:24:41]

The CQ bit was checked by henrik.lundin@webrtc.org

[commit-bot: I haz the power, 2015-11-02 11:24:51]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1425133002/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1425133002/20001

[commit-bot: I haz the power, 2015-11-02 11:26:04]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-11-02 11:26:09]

Patchset 2 (id:??) landed as
https://crrev.com/9bc2667fa6deee5d4162b13a878481640a58cce5
Cr-Commit-Position: refs/heads/master@{#10476}