Delete three class declarations that we don't provide implementations anymore.

This can be removed now that https://codereview.appspot.com/6650055/ was landed
in r5942.

R=epoger@google.com,reed@google.com

Review URL: https://codereview.appspot.com/6677044

git-svn-id: http://skia.googlecode.com/svn/trunk@5967 2bbb7eff-a529-9590-31e7-b0007b416f81
1 file changed