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

Update {virtual,override,final} to follow C++11 style chrome/browser/chromeos/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=jhawkins@chromium.org

Committed: https://crrev.com/da4362da0eed814fe3af6b5d38f8cd8147ba1b81
Cr-Commit-Position: refs/heads/master@{#311757}

[James Hawkins, 2015-01-15 21:34:56]

lgtm

[dcheng, 2015-01-15 21:35:51]

The CQ bit was checked by dcheng@chromium.org

[commit-bot: I haz the power, 2015-01-15 21:38:15]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/854053002/1

[commit-bot: I haz the power, 2015-01-15 23:08:50]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-01-15 23:10:44]

Patchset 1 (id:??) landed as
https://crrev.com/da4362da0eed814fe3af6b5d38f8cd8147ba1b81
Cr-Commit-Position: refs/heads/master@{#311757}