Blink doesn't use them any more, and they have no other known users either.

BUG=
R=dcarney@chromium.org, svenpanne@chromium.org

Review URL: https://codereview.chromium.org/16124004

Patch from Marja Hölttä <marja@chromium.org>.

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@14872 ce2b1a6d-e550-0410-aec6-3dcde31c8c00