Update {virtual,override,final} to follow C++11 style in chrome/browser/chromeos/settings.

Update {virtual,override,final} to follow C++11 style in chrome/browser/chromeos/settings.

The Google style guide states that only one of {virtual,override,final}
should be used for each declaration, since override implies virtual and
final implies both virtual and override.

This patch was automatically generated with a ChromeOS build using a
variation of https://codereview.chromium.org/598073004.

BUG=417463
R=mnissler@chromium.org

Committed: https://crrev.com/0e941015b1284d3833cd03c6c37d0192e64efa28
Cr-Commit-Position: refs/heads/master@{#311868}

[Mattias Nissler (ping if slow), 2015-01-16 08:49:12]

LGTM

[Mattias Nissler (ping if slow), 2015-01-16 08:49:16]

The CQ bit was checked by mnissler@chromium.org

[commit-bot: I haz the power, 2015-01-16 08:49:48]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/851123003/1

[commit-bot: I haz the power, 2015-01-16 11:36:53]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-01-16 11:38:55]

Patchset 1 (id:??) landed as
https://crrev.com/0e941015b1284d3833cd03c6c37d0192e64efa28
Cr-Commit-Position: refs/heads/master@{#311868}