Update {virtual,override,final} to follow C++11 style in chrome/browser/chromeos/input_method.

Update {virtual,override,final} to follow C++11 style in chrome/browser/chromeos/input_method.

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 a ChromeOS build using a
variation of https://codereview.chromium.org/598073004.

BUG=417463
R=zork@chromium.org

Committed: https://crrev.com/88b646e4232226053540eac1600967780a5a357b
Cr-Commit-Position: refs/heads/master@{#311788}

[Zachary Kuznia, 2015-01-15 23:07:51]

lgtm

[dcheng, 2015-01-15 23:10:30]

The CQ bit was checked by dcheng@chromium.org

[commit-bot: I haz the power, 2015-01-15 23:11:20]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/796693005/1

[commit-bot: I haz the power, 2015-01-16 00:45:16]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-01-16 00:46:40]

Patchset 1 (id:??) landed as
https://crrev.com/88b646e4232226053540eac1600967780a5a357b
Cr-Commit-Position: refs/heads/master@{#311788}