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

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

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 manually generated using a regex and a text editor.

BUG=417463
Committed: https://crrev.com/bc76161f2f357116c647446afdc4de083712224a
Cr-Commit-Position: refs/heads/master@{#327173}

[ncarter (slow), 2015-04-23 03:58:05]

nick@chromium.org changed reviewers:
+ alekseys@chromium.org

[ncarter (slow), 2015-04-23 03:58:06]

alekseys: please review

[ncarter (slow), 2015-04-24 16:14:16]

aleksey: ping

[Aleksey Shlyapnikov, 2015-04-27 21:43:26]

lgtm

[Nico, 2015-04-27 21:43:47]

The CQ bit was checked by thakis@chromium.org

[commit-bot: I haz the power, 2015-04-27 21:44:13]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1101023002/1

[commit-bot: I haz the power, 2015-04-27 23:30:58]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-04-27 23:31:45]

Patchset 1 (id:??) landed as
https://crrev.com/bc76161f2f357116c647446afdc4de083712224a
Cr-Commit-Position: refs/heads/master@{#327173}