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=nasko@chromium.org

Committed: https://crrev.com/48d97c5da05500312e7262d32ffd42b3fbb1c38e
Cr-Commit-Position: refs/heads/master@{#314610}

[mlamouri (slow - plz ping), 2015-02-04 10:11:46]

mlamouri@chromium.org changed reviewers:
+ mlamouri@chromium.org

[mlamouri (slow - plz ping), 2015-02-04 10:11:47]

owning a couple of files there but all lgtm

[nasko, 2015-02-04 17:53:48]

LGTM

[dcheng, 2015-02-04 18:37:46]

The CQ bit was checked by dcheng@chromium.org

[commit-bot: I haz the power, 2015-02-04 18:38:36]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/884103004/1

[commit-bot: I haz the power, 2015-02-04 20:03:50]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-02-04 20:04:41]

Patchset 1 (id:??) landed as
https://crrev.com/48d97c5da05500312e7262d32ffd42b3fbb1c38e
Cr-Commit-Position: refs/heads/master@{#314610}