Remove the distinction between informational and warning infobar

Remove the distinction between informational and warning infobar

The need to make the distinction between the two types of infobars has
disappeared with the new design of the infobars.

BUG=None

Committed: https://crrev.com/7764ad3d29cf888a78f0d4d513d0c4f76650d335
Cr-Commit-Position: refs/heads/master@{#318896}

[sdefresne, 2015-03-03 10:33:39]

sdefresne@chromium.org changed reviewers:
+ droger@chromium.org

[sdefresne, 2015-03-03 10:33:40]

PTAL

[droger, 2015-03-03 17:03:20]

The CQ bit was checked by droger@chromium.org

[droger, 2015-03-03 17:03:21]

lgtm

[commit-bot: I haz the power, 2015-03-03 17:03:50]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/975663002/1

[commit-bot: I haz the power, 2015-03-03 17:07:42]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-03-03 17:08:16]

Patchset 1 (id:??) landed as
https://crrev.com/7764ad3d29cf888a78f0d4d513d0c4f76650d335
Cr-Commit-Position: refs/heads/master@{#318896}