Fix not correctly allowing the 'require' keyword in shaders enabling EXT_draw_buffers. TRAC #22888 Signed-off-by: Nicolas Capens Signed-off-by: Shannon Woods Author: Jamie Madill git-svn-id: https://angleproject.googlecode.com/svn/branches/es3proto@2156 736b8ea6-26fd-11df-bfd4-992fa37f6226