- The states weren't being set properly to replicate the menu item
  highlight effect. The button background needs to be STATE_SELECTED
  while the actual widget needs PRELIGHT. This removes a bunch of
  crud.
- The fullscreen button needs to be tinted multiple times to the
  different label states. Now the fullscreen icon is the correct
  label color. Required adding infrastructure for GtkIconSets.

BUG=45757
TEST=All labels and images in buttons should match the normal and
prelight states of the labels in normal menu items. Make sure to
try themes that have different normal and prelight states (DarkLooks)
and themes that have the same color (Ambiance).

Review URL: http://codereview.chromium.org/2864044

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@51805 0039d316-1c4b-4281-b951-d872f2087c98