Remove VCM_*_PAYLOAD_TYPE constants.

Remove VCM_*_PAYLOAD_TYPE constants.

These payload types aren't directly connected to any payload type, and
the payload type still has to be negotiated externally. As such these
constants are just a source of confusion.

BUG=
R=stefan@webrtc.org

Committed: https://crrev.com/a7d70546ad40f535b76b1ef57afc28bcba8ce09f
Cr-Commit-Position: refs/heads/master@{#9546}

[pbos-webrtc, 2015-07-07 13:03:59]

PTAL

[stefan-webrtc, 2015-07-07 13:04:57]

The CQ bit was checked by stefan@webrtc.org

[stefan-webrtc, 2015-07-07 13:04:57]

lgtm

[commit-bot: I haz the power, 2015-07-07 13:05:00]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1215603003/1

[commit-bot: I haz the power, 2015-07-07 13:06:35]

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

[commit-bot: I haz the power, 2015-07-07 13:06:36]

Try jobs failed on following builders:
  win_rel on tryserver.webrtc (JOB_FAILED,
http://build.chromium.org/p/tryserver.webrtc/builders/win_rel/builds/8411)

(exceeded global retry quota)

[pbos-webrtc, 2015-07-07 13:16:50]

The CQ bit was checked by pbos@webrtc.org

[commit-bot: I haz the power, 2015-07-07 13:17:00]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1215603003/1

[commit-bot: I haz the power, 2015-07-07 13:18:53]

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

[commit-bot: I haz the power, 2015-07-07 13:18:53]

Try jobs failed on following builders:
  win_x64_rel on tryserver.webrtc (JOB_FAILED,
http://build.chromium.org/p/tryserver.webrtc/builders/win_x64_rel/builds/8210)

(exceeded global retry quota)

[pbos-webrtc, 2015-07-07 13:29:29]

The CQ bit was checked by pbos@webrtc.org

[commit-bot: I haz the power, 2015-07-07 13:29:40]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1215603003/1

[commit-bot: I haz the power, 2015-07-07 13:31:41]

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

[commit-bot: I haz the power, 2015-07-07 13:31:42]

Try jobs failed on following builders:
  win_drmemory_light on tryserver.webrtc (JOB_FAILED,
http://build.chromium.org/p/tryserver.webrtc/builders/win_drmemory_light/buil...)
  win_x64_rel on tryserver.webrtc (JOB_FAILED,
http://build.chromium.org/p/tryserver.webrtc/builders/win_x64_rel/builds/8212)

(exceeded global retry quota)

[pbos-webrtc, 2015-07-07 13:57:25]

The CQ bit was checked by pbos@webrtc.org

[commit-bot: I haz the power, 2015-07-07 13:57:36]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1215603003/1

[commit-bot: I haz the power, 2015-07-07 14:35:53]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-07-07 14:36:06]

Patchset 1 (id:??) landed as
https://crrev.com/a7d70546ad40f535b76b1ef57afc28bcba8ce09f
Cr-Commit-Position: refs/heads/master@{#9546}