use c++03 style enum scope

use c++03 style enum scope

Followup to https://codereview.chromium.org/411973004

We haven't officially switched over to using c++11 everywhere
yet, so this patch replaces c++11 style enum scope with c++03 style scope.

BUG=392621
Committed: https://crrev.com/23a9a22b232c86d47edc1b6c7f7e9e677931252e
Cr-Commit-Position: refs/heads/master@{#292902}

[Mostyn Bramley-Moore, 2014-09-01 19:33:46]

mostynb@opera.com changed reviewers:
+ jkarlin@chromium.org, michaeln@chromium.org, sigbjornf@opera.com

[Mostyn Bramley-Moore, 2014-09-01 19:34:21]

@michaeln, jkarlin: please take a look at this tiny patch.

[nhiroki, 2014-09-02 01:59:26]

nhiroki@chromium.org changed reviewers:
+ nhiroki@chromium.org

[nhiroki, 2014-09-02 01:59:26]

LGTM (other reviewers seems to be on the national holiday)

[Mostyn Bramley-Moore, 2014-09-02 06:25:41]

The CQ bit was checked by mostynb@opera.com

[commit-bot: I haz the power, 2014-09-02 06:26:20]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/mostynb@opera.com/526193002/1

[commit-bot: I haz the power, 2014-09-02 07:22:35]

Committed patchset #1 (id:1) as e728f7b0e2d56628891c1b55bb30016b6019133a

[commit-bot: I haz the power, 2014-09-10 03:17:47]

Patchset 1 (id:??) landed as
https://crrev.com/23a9a22b232c86d47edc1b6c7f7e9e677931252e
Cr-Commit-Position: refs/heads/master@{#292902}