Undo the changes to LabelButton from r266097

Undo the changes to LabelButton from r266097

This caused breakage because many places create a LabelButton then call SetBorder. By calling SetBorder whenever the NativeTheme changes, the custom border is overridden.

BUG=367614, 367625, 367607
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=266736

[Evan Stade, 2014-04-28 19:44:39]

revert first, fix Linux Aura later.

[sky, 2014-04-28 20:40:59]

LGTM

[Evan Stade, 2014-04-28 21:54:15]

The CQ bit was checked by estade@chromium.org

[commit-bot: I haz the power, 2014-04-28 21:55:30]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/estade@chromium.org/256103006/1

[commit-bot: I haz the power, 2014-04-28 22:38:46]

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

[commit-bot: I haz the power, 2014-04-28 22:38:46]

Try jobs failed on following builders:
  tryserver.chromium on win_chromium_rel

[Evan Stade, 2014-04-28 22:52:22]

The CQ bit was checked by estade@chromium.org

[commit-bot: I haz the power, 2014-04-28 22:52:39]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/estade@chromium.org/256103006/1

[commit-bot: I haz the power, 2014-04-29 02:00:27]

Change committed as 266736