Remove CSS Exclusions leftovers

https://codereview.chromium.org/60013004 started this but must have missed these.

Review URL: https://codereview.chromium.org/359023002

git-svn-id: svn://svn.chromium.org/blink/trunk@177167 bbb929c8-8fbe-4397-9dbb-9b2b20218538