Align ChannelLayout comments with kChannelOrderings values

Align ChannelLayout comments with kChannelOrderings values

The documentation of several ChannelLayout enumerators was at odds with
the values in kChannelOrderings.

Committed: https://crrev.com/bf062c1169b111370d27b4ce7fec527bc3cc5d5d
Cr-Commit-Position: refs/heads/master@{#324481}

[wdzierzanowski, 2015-04-09 08:20:49]

wdzierzanowski@opera.com changed reviewers:
+ dalecurtis@chromium.org

[wdzierzanowski, 2015-04-09 08:20:49]

PTAL dalecurtis.

I'm assuming the values in kChannelOrderings are the ultimate source of truth,
so I didn't check them in any way.

[DaleCurtis, 2015-04-09 16:53:49]

lgtm, thanks for the cleanup!

[wdzierzanowski, 2015-04-09 17:18:50]

The CQ bit was checked by wdzierzanowski@opera.com

[commit-bot: I haz the power, 2015-04-09 17:19:55]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1078463003/1

[commit-bot: I haz the power, 2015-04-09 18:41:24]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-04-09 18:42:16]

Patchset 1 (id:??) landed as
https://crrev.com/bf062c1169b111370d27b4ce7fec527bc3cc5d5d
Cr-Commit-Position: refs/heads/master@{#324481}