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

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

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/0e1afc9112d09515b380002645efc21ba3a87122
Cr-Commit-Position: refs/heads/master@{#326451}

[ncarter (slow), 2015-04-23 04:19:46]

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

[ncarter (slow), 2015-04-23 04:19:46]

satorux: please take a look

[satorux1, 2015-04-23 04:32:01]

lgtm

[ncarter (slow), 2015-04-23 04:38:06]

The CQ bit was checked by nick@chromium.org

[commit-bot: I haz the power, 2015-04-23 04:38:23]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1055053003/1

[commit-bot: I haz the power, 2015-04-23 04:42:06]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-04-23 04:43:09]

Patchset 1 (id:??) landed as
https://crrev.com/0e1afc9112d09515b380002645efc21ba3a87122
Cr-Commit-Position: refs/heads/master@{#326451}