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

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

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/80b796a8539bf302d4d4aa420356d0f8c0d46063
Cr-Commit-Position: refs/heads/master@{#327154}

[ncarter (slow), 2015-04-23 14:09:16]

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

[ncarter (slow), 2015-04-23 14:09:17]

Hi vitalybuka@ -- please review! thanks.

[ncarter (slow), 2015-04-24 16:11:39]

vitaly: friendly ping

[Vitaly Buka (NO REVIEWS), 2015-04-27 21:42:23]

The CQ bit was checked by vitalybuka@chromium.org

[Vitaly Buka (NO REVIEWS), 2015-04-27 21:42:23]

lgtm

[commit-bot: I haz the power, 2015-04-27 21:42:57]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1100633004/20001

[commit-bot: I haz the power, 2015-04-27 22:15:05]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-04-27 22:16:25]

Patchset 2 (id:??) landed as
https://crrev.com/80b796a8539bf302d4d4aa420356d0f8c0d46063
Cr-Commit-Position: refs/heads/master@{#327154}