message center: Make BoundedLabel override OnPaint instead of Paint.

message center: Make BoundedLabel override OnPaint instead of Paint.

This makes the BoundedLabel override View::OnPaint, allowing us to make
View::Paint non-virtual.

The functional difference is that Paint() calls PaintCommon() which:
 - Early outs if not visible
 - Paints any children

The BoundedLabel is used by NotificationView, but no children are ever
added to it and it's not exposed outside the class. So it's safe to
convert it to use OnPaint() and remove the visible early out.

R=dewittj@chromium.org, mukai@chromium.org, stevenjb@chromium.org
BUG=466426
Committed: https://crrev.com/dfbb1944e145e37b52b6c0665c0c686fdc7ca563
Cr-Commit-Position: refs/heads/master@{#322082}

[danakj, 2015-03-24 20:28:22]

Hello could one of y'all please have a look?

[Jun Mukai, 2015-03-24 21:50:04]

lgtm

[danakj, 2015-03-24 22:04:24]

The CQ bit was checked by danakj@chromium.org

[commit-bot: I haz the power, 2015-03-24 22:05:02]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1035553002/20001

[commit-bot: I haz the power, 2015-03-24 22:37:42]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-03-24 22:38:38]

Patchset 2 (id:??) landed as
https://crrev.com/dfbb1944e145e37b52b6c0665c0c686fdc7ca563
Cr-Commit-Position: refs/heads/master@{#322082}