docs: Don't document cogl_flush_gl_state as public API

This function was #if 0'd before we released Clutter 1.0 so there's no
implementation of it.  At some point we thought it might assist with
developers breaking out into raw OpenGL.  Breaking out to raw GL is a
difficult problem though so we decided instead we will wait for a specific
use case to arrise before trying to support it.

clutter/cogl/cogl/cogl.c

@@ -570,14 +570,6 @@ cogl_disable_fog (void)
   glDisable (GL_FOG);
 }
 
-#if 0
-void
-cogl_flush_gl_state (int flags)
-{
-  _cogl_draw_buffer_flush_state (_cogl_get_draw_buffer (), 0);
-}
-#endif
-
 void
 cogl_flush (void)
 {

clutter/cogl/cogl/cogl.h

@@ -952,28 +952,6 @@ void            cogl_end_gl (void);
 
 void            _cogl_destroy_context          (void);
 
-/* XXX: Removed before we release Clutter 1.0 since the implementation
- * wasn't complete, and so we assume no one is using this yet. Util we
- * have some one with a good usecase, we can't pretend to support breaking
- * out into raw OpenGL. */
-
-#if 0
-/*
- * cogl_flush_gl_state:
- * @flags: flags controlling what is flushed; currently unused, pass in 0
- *
- * As an optimization, COGL functions may not immediately modify GL's
- * state, instead batching up changes and applying them "just in
- * time."  Unapplied state could include glEnable() flags and the
- * current transformation matrix among other examples. If you want to
- * use GL directly, you need to flush any state COGL may have kept
- * around. cogl_flush_gl_state() syncs all of COGL's state to GL.
- *
- * Since: 1.0
- */
-void            cogl_flush_gl_state         (int      flags);
-#endif
-
 /*< private >*/
 #define COGL_DRIVER_ERROR (_cogl_driver_error_quark ())
 

doc/reference/cogl/cogl-sections.txt

@@ -119,7 +119,6 @@ cogl_read_pixels_flags_get_type
 cogl_shader_type_get_type
 cogl_texture_flags_get_type
 cogl_vertices_mode_get_type
-cogl_flush_gl_state
 </SECTION>
 
 <SECTION>