Update {virtual,override,final} to follow C++11 style.

Update {virtual,override,final} to follow C++11 style.

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 an OS=android build using a
variation of https://codereview.chromium.org/598073004.

BUG=417463
R=sgurun@chromium.org

Committed: https://crrev.com/9f9f934ab10ff8bf1922ccc23e449167237d98b9
Cr-Commit-Position: refs/heads/master@{#314467}

[sgurun-gerrit only, 2015-02-04 00:59:52]

On 2015/02/04 00:46:24, dcheng wrote:

lgtm

[dcheng, 2015-02-04 01:12:08]

The CQ bit was checked by dcheng@chromium.org

[commit-bot: I haz the power, 2015-02-04 01:12:53]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/893273003/1

[commit-bot: I haz the power, 2015-02-04 01:50:45]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-02-04 01:52:26]

Patchset 1 (id:??) landed as
https://crrev.com/9f9f934ab10ff8bf1922ccc23e449167237d98b9
Cr-Commit-Position: refs/heads/master@{#314467}