Committing http://codereview.chromium.org/7084022/ for Satoshi Matsuzaki.

BUG=37501
TEST=make sure maximized incognito app window has same color as regular incognito app window.
Review URL: http://codereview.chromium.org/7112034

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@88002 0039d316-1c4b-4281-b951-d872f2087c98