Fix appearance of disabled VectorIconButtons.

Fix appearance of disabled VectorIconButtons.

Ironically, removing OnEnabledChanged() fixes this bug. Not calling
through to the parent class's implementation was problematic, but it
turns out that handling changes to the enable state isn't necessary
anyway since that's done with the state parameter of
ImageButton::SetImage().

BUG=645353
Committed: https://crrev.com/4aabce05f776aa8c56e1d208f9c27423ea90690b
Cr-Commit-Position: refs/heads/master@{#418431}

[Evan Stade, 2016-09-13 17:58:01]

estade@chromium.org changed reviewers:
+ sadrul@chromium.org

[sadrul, 2016-09-13 22:45:26]

lgtm

[Evan Stade, 2016-09-13 23:04:44]

The CQ bit was checked by estade@chromium.org

[commit-bot: I haz the power, 2016-09-13 23:05:25]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-09-14 00:15:25]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-09-14 00:16:59]

Description was changed from

==========
Fix appearance of disabled VectorIconButtons.

Ironically, removing OnEnabledChanged() fixes this bug. Not calling
through to the parent class's implementation was problematic, but it
turns out that handling changes to the enable state isn't necessary
anyway since that's done with the state parameter of
ImageButton::SetImage().

BUG=645353
==========

to

==========
Fix appearance of disabled VectorIconButtons.

Ironically, removing OnEnabledChanged() fixes this bug. Not calling
through to the parent class's implementation was problematic, but it
turns out that handling changes to the enable state isn't necessary
anyway since that's done with the state parameter of
ImageButton::SetImage().

BUG=645353

Committed: https://crrev.com/4aabce05f776aa8c56e1d208f9c27423ea90690b
Cr-Commit-Position: refs/heads/master@{#418431}
==========

[commit-bot: I haz the power, 2016-09-14 00:17:00]

Patchset 1 (id:??) landed as
https://crrev.com/4aabce05f776aa8c56e1d208f9c27423ea90690b
Cr-Commit-Position: refs/heads/master@{#418431}