Roll libvpx: cc9c0c:097fdc

Roll libvpx: cc9c0c:097fdc

Cherry-pick potential divide-by-zero fix
https://codereview.chromium.org/877783004

This also removes the last remnants of the AVX attempts:
https://codereview.chromium.org/873313005
It should have been a no-op since it only changes cpu detection. The functions
themselves have been disabled and are not compiled so this is the last remaining
related change.

CQ_INCLUDE_TRYBOTS=tryserver.chromium.win:win_chromium_vista_rel_ng

R=tomfinegan@chromium.org
BUG=396572
Committed: https://crrev.com/a5300b3ac2f7825a9c9661a6a197e1c84ecd5ab0
Cr-Commit-Position: refs/heads/master@{#313354}

[Johann, 2015-01-27 17:40:41]

I certainly hope this change didn't cause the GPU to crash. The Vista bot is
required this time so hopefully we'll know immediately if it causes an issue.

[Tom Finegan, 2015-01-27 19:00:53]

lgtm

[Johann, 2015-01-27 19:01:00]

The CQ bit was checked by johannkoenig@google.com

[commit-bot: I haz the power, 2015-01-27 19:02:33]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/877123002/1

[commit-bot: I haz the power, 2015-01-27 19:58:04]

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

[commit-bot: I haz the power, 2015-01-27 19:58:04]

Try jobs failed on following builders:
  win_chromium_x64_rel_ng on tryserver.chromium.win
(http://build.chromium.org/p/tryserver.chromium.win/builders/win_chromium_x64_...)

[Johann, 2015-01-27 19:59:42]

The CQ bit was checked by johannkoenig@google.com

[commit-bot: I haz the power, 2015-01-27 20:00:52]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/877123002/1

[commit-bot: I haz the power, 2015-01-27 20:52:33]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-01-27 20:53:35]

Patchset 1 (id:??) landed as
https://crrev.com/a5300b3ac2f7825a9c9661a6a197e1c84ecd5ab0
Cr-Commit-Position: refs/heads/master@{#313354}