We always build with skia now. This change removes dead code, and unnecessary
USE_SKIA guards.
BUG=110881
Review URL: https://chromiumcodereview.appspot.com/12406010
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@190031 0039d316-1c4b-4281-b951-d872f2087c98