[cogl] remove redundant _cogl_clip_stack_dirty() api

[Robert Bragg <rbragg src gnome org>]

commit 6d1bf9a0d40277b14fc52488bc59c0088039d055
Author: Robert Bragg <robert linux intel com>
Date:   Mon Nov 21 17:37:41 2011 +0000

    remove redundant _cogl_clip_stack_dirty() api
    
    The only place we were calling _cogl_clip_stack_dirty() was when
    changing the current draw_buffer which also implies a change in
    the current clip stack. _cogl_clip_stack_flush() would already
    be able to quickly determine that the clip stack has changed by
    checking ctx->current_clip_stack so there isn't really any need
    to explicitly mark the clip_stack state as dirty.
    
    Reviewed-by: Neil Roberts <neil linux intel com>

 cogl/cogl-clip-stack.c  |   12 ------------
 cogl/cogl-clip-stack.h  |    3 ---
 cogl/cogl-framebuffer.c |    2 --
 3 files changed, 0 insertions(+), 17 deletions(-)
---
diff --git a/cogl/cogl-clip-stack.c b/cogl/cogl-clip-stack.c
index b9db676..8600f30 100644
--- a/cogl/cogl-clip-stack.c
+++ b/cogl/cogl-clip-stack.c
@@ -1003,15 +1003,3 @@ _cogl_clip_stack_flush (CoglClipStack *stack,
 
   ctx->current_clip_stack_uses_stencil = using_stencil_buffer;
 }
-
-void
-_cogl_clip_stack_dirty (void)
-{
-  _COGL_GET_CONTEXT (ctx, NO_RETVAL);
-
-  if (ctx->current_clip_stack_valid)
-    {
-      ctx->current_clip_stack_valid = FALSE;
-      _cogl_clip_stack_unref (ctx->current_clip_stack);
-    }
-}
diff --git a/cogl/cogl-clip-stack.h b/cogl/cogl-clip-stack.h
index 0a77a18..a7b9346 100644
--- a/cogl/cogl-clip-stack.h
+++ b/cogl/cogl-clip-stack.h
@@ -215,7 +215,4 @@ _cogl_clip_stack_ref (CoglClipStack *stack);
 void
 _cogl_clip_stack_unref (CoglClipStack *stack);
 
-void
-_cogl_clip_stack_dirty (void);
-
 #endif /* __COGL_CLIP_STACK_H */
diff --git a/cogl/cogl-framebuffer.c b/cogl/cogl-framebuffer.c
index be0ee79..a7b0e08 100644
--- a/cogl/cogl-framebuffer.c
+++ b/cogl/cogl-framebuffer.c
@@ -1102,8 +1102,6 @@ notify_buffers_changed (CoglFramebuffer *old_draw_buffer,
   ctx->dirty_bound_framebuffer = 1;
   ctx->dirty_gl_viewport = 1;
 
-  _cogl_clip_stack_dirty ();
-
   if (old_draw_buffer && new_draw_buffer)
     {
       /* If the two draw framebuffers have a different color mask then