Implemented glInvalidateFramebuffer and glInvalidateSubFramebuffer. TRAC #23133 Signed-off-by: Jamie Madill Signed-off-by: Shannon Woods Author: Geoff Lang git-svn-id: https://angleproject.googlecode.com/svn/branches/es3proto@2335 736b8ea6-26fd-11df-bfd4-992fa37f6226