Remove the preprocessor symbol WEBRTC_CODEC_AVT (it was always defined)

Remove the preprocessor symbol WEBRTC_CODEC_AVT (it was always defined)

BUG=webrtc:4557
Committed: https://crrev.com/1f9baab753be55a7c6d31c84a5470fe646936edd
Cr-Commit-Position: refs/heads/master@{#9960}

[kwiberg-webrtc, 2015-09-14 13:56:11]

kwiberg@webrtc.org changed reviewers:
+ henrik.lundin@webrtc.org, tina.legrand@webrtc.org

[hlundin-webrtc, 2015-09-15 13:07:28]

lgtm

[tlegrand-webrtc, 2015-09-16 07:50:25]

lgtm

[kwiberg-webrtc, 2015-09-16 07:52:53]

The CQ bit was checked by kwiberg@webrtc.org

[commit-bot: I haz the power, 2015-09-16 07:53:05]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1338283002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1338283002/1

[commit-bot: I haz the power, 2015-09-16 07:54:26]

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

[commit-bot: I haz the power, 2015-09-16 07:54:27]

Try jobs failed on following builders:
  ios64_sim on tryserver.webrtc (JOB_FAILED,
http://build.chromium.org/p/tryserver.webrtc/builders/ios64_sim/builds/2070)
  linux_gn_rel on tryserver.webrtc (JOB_FAILED,
http://build.chromium.org/p/tryserver.webrtc/builders/linux_gn_rel/builds/5520)
  mac_baremetal on tryserver.webrtc (JOB_FAILED,
http://build.chromium.org/p/tryserver.webrtc/builders/mac_baremetal/builds/7360)

[kwiberg-webrtc, 2015-09-16 17:27:47]

The CQ bit was checked by kwiberg@webrtc.org

[kwiberg-webrtc, 2015-09-16 17:27:47]

The patchset sent to the CQ was uploaded after l-g-t-m from
henrik.lundin@webrtc.org, tina.legrand@webrtc.org
Link to the patchset: https://codereview.webrtc.org/1338283002/#ps20001 (title:
"rebase")

[commit-bot: I haz the power, 2015-09-16 17:28:04]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1338283002/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1338283002/20001

[commit-bot: I haz the power, 2015-09-16 19:28:26]

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

[commit-bot: I haz the power, 2015-09-16 19:28:26]

Try jobs failed on following builders:
  android on tryserver.webrtc (JOB_TIMED_OUT, no build URL)
  android_arm64_rel on tryserver.webrtc (JOB_TIMED_OUT, no build URL)
  android_rel on tryserver.webrtc (JOB_TIMED_OUT, no build URL)
  linux_baremetal on tryserver.webrtc (JOB_TIMED_OUT, no build URL)
  mac_baremetal on tryserver.webrtc (JOB_TIMED_OUT, no build URL)
  win_baremetal on tryserver.webrtc (JOB_TIMED_OUT, no build URL)
  win_drmemory_light on tryserver.webrtc (JOB_TIMED_OUT, no build URL)

[kwiberg-webrtc, 2015-09-17 02:28:38]

The CQ bit was checked by kwiberg@webrtc.org

[commit-bot: I haz the power, 2015-09-17 02:28:49]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1338283002/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1338283002/20001

[commit-bot: I haz the power, 2015-09-17 02:29:48]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-09-17 02:29:58]

Patchset 2 (id:??) landed as
https://crrev.com/1f9baab753be55a7c6d31c84a5470fe646936edd
Cr-Commit-Position: refs/heads/master@{#9960}