Files.app: Add focus feedback on dialog footer.

Files.app: Add focus feedback on dialog footer.

Added rounded focus ring for controls on dialog footer.
Tab order should be reconsidered later as accessibility improvement.

BUG=402344
TEST=manually tested

Committed: https://crrev.com/ff372678a3c46ee4522375964fb764785a3eff70
Cr-Commit-Position: refs/heads/master@{#317293}

[fukino, 2015-02-20 11:01:00]

fukino@chromium.org changed reviewers:
+ hirono@chromium.org

[fukino, 2015-02-20 11:01:01]

PTAL. Thanks!

[hirono, 2015-02-20 11:03:50]

lgtm!

[fukino, 2015-02-20 11:06:03]

Thanks!

[fukino, 2015-02-20 11:08:14]

The CQ bit was checked by fukino@chromium.org

[commit-bot: I haz the power, 2015-02-20 11:09:06]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/938383002/1

[commit-bot: I haz the power, 2015-02-20 11:35:09]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-02-20 11:36:03]

Patchset 1 (id:??) landed as
https://crrev.com/ff372678a3c46ee4522375964fb764785a3eff70
Cr-Commit-Position: refs/heads/master@{#317293}