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

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

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
Committed: https://crrev.com/aef52682b97c29f94ceb9a9750e29eecad58b416
Cr-Commit-Position: refs/heads/master@{#314943}

[dcheng, 2015-02-06 01:09:38]

dcheng@chromium.org changed reviewers:
+ thestig@chromium.org

[Lei Zhang, 2015-02-06 01:14:39]

lgtm, nut sure if I'm an owner here though.

[dcheng, 2015-02-06 01:19:16]

The CQ bit was checked by dcheng@chromium.org

[commit-bot: I haz the power, 2015-02-06 01:20:00]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/898173002/1

[commit-bot: I haz the power, 2015-02-06 01:56:27]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-02-06 01:57:29]

Patchset 1 (id:??) landed as
https://crrev.com/aef52682b97c29f94ceb9a9750e29eecad58b416
Cr-Commit-Position: refs/heads/master@{#314943}