Fix proprietary codecs builds for GN.

Fix proprietary codecs builds for GN.

BUG=none
TEST=mojo plays mp3s.

Committed: https://crrev.com/cede870bcc0e176edf2eebb8d379561005ce0420
Cr-Commit-Position: refs/heads/master@{#300738}

[DaleCurtis, 2014-10-21 00:24:45]

dalecurtis@chromium.org changed reviewers:
+ xhwang@chromium.org

[xhwang, 2014-10-22 16:33:28]

lgtm

[DaleCurtis, 2014-10-22 17:51:04]

The CQ bit was checked by dalecurtis@chromium.org

[commit-bot: I haz the power, 2014-10-22 17:54:25]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/664303002/1

[commit-bot: I haz the power, 2014-10-22 19:09:38]

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

[commit-bot: I haz the power, 2014-10-22 19:09:39]

Try jobs failed on following builders:
  linux_chromium_asan_rel on tryserver.chromium.linux
(http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)

[DaleCurtis, 2014-10-22 19:13:15]

The CQ bit was checked by dalecurtis@chromium.org

[commit-bot: I haz the power, 2014-10-22 19:14:37]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/664303002/1

[commit-bot: I haz the power, 2014-10-22 20:19:46]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2014-10-22 20:21:09]

Patchset 1 (id:??) landed as
https://crrev.com/cede870bcc0e176edf2eebb8d379561005ce0420
Cr-Commit-Position: refs/heads/master@{#300738}