Implement the API-side logic GetUniformBlockIndex. Functionality depends on shader support. TRAC #22858 Signed-off-by: Geoff Lang Signed-off-by: Nicolas Capens Author: Jamie Madill git-svn-id: https://angleproject.googlecode.com/svn/branches/es3proto@2307 736b8ea6-26fd-11df-bfd4-992fa37f6226