GTK: in gtk theme mode, when a chrome button is showing a menu, make it look depressed.
GTK: in gtk theme mode, when a chrome button is showing a menu, make it look depressed.

BUG=21053
TEST=app menu

Review URL: http://codereview.chromium.org/328001

git-svn-id: http://src.chromium.org/svn/trunk/src@29837 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

Former-commit-id: 3611634fce5d142025bcb252c20c2ea956a0c9b1
meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser