gtk: Remove a couple of functions from the API and define them where they are used instead.

BUG=none
R=sky@chromium.org

Review URL: https://codereview.chromium.org/23548044

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@224773 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 224773