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

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

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=sky@chromium.org

Committed: https://crrev.com/77fc7b7776899bbaee5bcb2a108c16d8796a60a6
Cr-Commit-Position: refs/heads/master@{#311792}

[sky, 2015-01-15 23:51:04]

LGTM

[dcheng, 2015-01-15 23:51:18]

The CQ bit was checked by dcheng@chromium.org

[commit-bot: I haz the power, 2015-01-15 23:53:04]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/834383004/1

[commit-bot: I haz the power, 2015-01-16 00:49:14]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-01-16 00:51:21]

Patchset 1 (id:??) landed as
https://crrev.com/77fc7b7776899bbaee5bcb2a108c16d8796a60a6
Cr-Commit-Position: refs/heads/master@{#311792}