Standardize usage of virtual/override/final in chrome/browser/extensions/

Standardize usage of virtual/override/final in chrome/browser/extensions/

This patch was automatically generated by applying clang fixit hints
generated by the plugin to the source tree.

BUG=417463
TBR=mek@chromium.org

Committed: https://crrev.com/ae36a4a3f2efd040be2e563b0bff0592b0a5b5a1
Cr-Commit-Position: refs/heads/master@{#300474}

[dcheng, 2014-10-21 10:22:24]

The CQ bit was checked by dcheng@chromium.org

[commit-bot: I haz the power, 2014-10-21 10:23:57]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/666153002/1

[Lei Zhang, 2014-10-21 10:32:27]

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

[Lei Zhang, 2014-10-21 10:32:30]

Drive by lgtm

It would be nice if the CLs can be a little smaller so that we don't get the
"Patch set is too large to download" error.

[dcheng, 2014-10-21 10:34:52]

Sorry, some directories are more annoying to split up than others. If only there
was some automation for this...

[commit-bot: I haz the power, 2014-10-21 11:54:33]

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

[commit-bot: I haz the power, 2014-10-21 11:54:37]

Try jobs failed on following builders:
  linux_chromium_rel_swarming on tryserver.chromium.linux
(http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)

[dcheng, 2014-10-21 11:58:13]

The CQ bit was checked by dcheng@chromium.org

[commit-bot: I haz the power, 2014-10-21 12:01:35]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/666153002/1

[commit-bot: I haz the power, 2014-10-21 12:36:49]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2014-10-21 13:10:05]

Patchset 1 (id:??) landed as
https://crrev.com/ae36a4a3f2efd040be2e563b0bff0592b0a5b5a1
Cr-Commit-Position: refs/heads/master@{#300474}