It is no longer used in public or private includes or by any users.
Change-Id: Id3803531b411dc7a565b2bb688505eb2c1212cfd
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/208661
Reviewed-by: Mike Klein <mtklein@google.com>
Commit-Queue: Ben Wagner <bungeman@google.com>