Adding telemetry WebRTC measurements for the audio codecs we support.

Adding telemetry WebRTC measurements for the audio codecs we support.

We'll now measure vital statistics for all audio codecs we support,
notably the CPU usage of the various codecs. The results on by Linux
box suggests Opus is the most expensive codec (but it presumably sounds
better). It will be interesting to see what results we will see on
Android and ChromeOS devices.

BUG=413577
Committed: https://crrev.com/efb8ed2ebbfa8403c7231c7cf6af787e4d13588d
Cr-Commit-Position: refs/heads/master@{#308338}

[phoglund_chromium, 2014-12-12 10:29:57]

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

[qyearsley, 2014-12-14 01:49:07]

On 2014/12/12 10:29:57, phoglund wrote:

Don't see any problems, lgtm.

[phoglund_chromium, 2014-12-15 09:44:10]

The CQ bit was checked by phoglund@chromium.org

[commit-bot: I haz the power, 2014-12-15 09:45:02]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/798903003/20001

[commit-bot: I haz the power, 2014-12-15 09:47:44]

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

[commit-bot: I haz the power, 2014-12-15 09:47:45]

Try jobs failed on following builders:
  ios_rel_device_ninja on tryserver.chromium.mac
(http://build.chromium.org/p/tryserver.chromium.mac/builders/ios_rel_device_ni...)
  win8_chromium_rel on tryserver.chromium.win
(http://build.chromium.org/p/tryserver.chromium.win/builders/win8_chromium_rel...)

[phoglund_chromium, 2014-12-15 10:08:20]

The CQ bit was checked by phoglund@chromium.org

[commit-bot: I haz the power, 2014-12-15 10:09:05]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/798903003/40001

[commit-bot: I haz the power, 2014-12-15 12:06:36]

Committed patchset #3 (id:40001)

[commit-bot: I haz the power, 2014-12-15 12:07:16]

Patchset 3 (id:??) landed as
https://crrev.com/efb8ed2ebbfa8403c7231c7cf6af787e4d13588d
Cr-Commit-Position: refs/heads/master@{#308338}