Remove unnecessary paintSkiaText wrapper

Remove paintSkiaText wrapper function that is no longer needed now that we always have SkTypeface.

R=bungeman@chromium.org

Review URL: https://codereview.chromium.org/209113002

git-svn-id: svn://svn.chromium.org/blink/trunk@169868 bbb929c8-8fbe-4397-9dbb-9b2b20218538