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=skyostil@chromium.org

Committed: https://crrev.com/f0217ba51893ea7cc776d843d035bec759fef9a0
Cr-Commit-Position: refs/heads/master@{#314853}

[Sami, 2015-02-05 11:37:39]

lgtm, thanks.

[dcheng, 2015-02-05 18:03:27]

The CQ bit was checked by dcheng@chromium.org

[commit-bot: I haz the power, 2015-02-05 18:04:23]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/897773002/1

[commit-bot: I haz the power, 2015-02-05 18:07:48]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-02-05 18:07:48]

Try jobs failed on following builders:
  ios_dbg_simulator on tryserver.chromium.mac
(http://build.chromium.org/p/tryserver.chromium.mac/builders/ios_dbg_simulator...)
  ios_rel_device_ng on tryserver.chromium.mac
(http://build.chromium.org/p/tryserver.chromium.mac/builders/ios_rel_device_ng...)
  ios_rel_device_ninja_ng on tryserver.chromium.mac
(http://build.chromium.org/p/tryserver.chromium.mac/builders/ios_rel_device_ni...)
  mac_chromium_compile_dbg_ng on tryserver.chromium.mac
(http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_comp...)
  mac_chromium_rel_ng on tryserver.chromium.mac
(http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_rel_...)

[dcheng, 2015-02-05 18:34:54]

New patchsets have been uploaded after l-g-t-m from skyostil@chromium.org

[dcheng, 2015-02-05 18:36:09]

The CQ bit was checked by dcheng@chromium.org

[commit-bot: I haz the power, 2015-02-05 18:36:42]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/897773002/20001

[commit-bot: I haz the power, 2015-02-05 19:27:11]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-02-05 19:28:24]

Patchset 2 (id:??) landed as
https://crrev.com/f0217ba51893ea7cc776d843d035bec759fef9a0
Cr-Commit-Position: refs/heads/master@{#314853}