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

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

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=thakis@chromium.org

Committed: https://crrev.com/6da56b3fcd5e45cd72a28bc88a2c2c42ebbfc59b
Cr-Commit-Position: refs/heads/master@{#311763}

[Nico, 2015-01-15 21:17:28]

lgtm!

[dcheng, 2015-01-15 21:24:18]

The CQ bit was checked by dcheng@chromium.org

[commit-bot: I haz the power, 2015-01-15 21:25:46]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/854043002/1

[commit-bot: I haz the power, 2015-01-15 23:25:23]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-01-15 23:26:38]

Patchset 1 (id:??) landed as
https://crrev.com/6da56b3fcd5e45cd72a28bc88a2c2c42ebbfc59b
Cr-Commit-Position: refs/heads/master@{#311763}