[mutter] cogl: Remove unused CoglPipelineFragend::passthrough

[Jonas Ådahl <jadahl src gnome org>]

commit e922c640efa70da43ee3869743e0a751f86b97b4
Author: Adam Jackson <ajax redhat com>
Date:   Thu Mar 7 13:52:33 2019 -0500

    cogl: Remove unused CoglPipelineFragend::passthrough
    
    https://gitlab.gnome.org/GNOME/mutter/merge_requests/819

 cogl/cogl/cogl-pipeline-private.h                | 1 -
 cogl/cogl/driver/gl/cogl-pipeline-fragend-glsl.c | 1 -
 cogl/cogl/driver/gl/cogl-pipeline-opengl.c       | 7 -------
 3 files changed, 9 deletions(-)
---
diff --git a/cogl/cogl/cogl-pipeline-private.h b/cogl/cogl/cogl-pipeline-private.h
index 93f31f406..4d6a589c1 100644
--- a/cogl/cogl/cogl-pipeline-private.h
+++ b/cogl/cogl/cogl-pipeline-private.h
@@ -429,7 +429,6 @@ typedef struct _CoglPipelineFragend
   gboolean (*add_layer) (CoglPipeline *pipeline,
                          CoglPipelineLayer *layer,
                          unsigned long layers_difference);
-  gboolean (*passthrough) (CoglPipeline *pipeline);
   gboolean (*end) (CoglPipeline *pipeline,
                    unsigned long pipelines_difference);
 
diff --git a/cogl/cogl/driver/gl/cogl-pipeline-fragend-glsl.c 
b/cogl/cogl/driver/gl/cogl-pipeline-fragend-glsl.c
index 6beed12eb..9019e12a6 100644
--- a/cogl/cogl/driver/gl/cogl-pipeline-fragend-glsl.c
+++ b/cogl/cogl/driver/gl/cogl-pipeline-fragend-glsl.c
@@ -1119,7 +1119,6 @@ const CoglPipelineFragend _cogl_pipeline_glsl_fragend =
 {
   _cogl_pipeline_fragend_glsl_start,
   _cogl_pipeline_fragend_glsl_add_layer,
-  NULL, /* passthrough */
   _cogl_pipeline_fragend_glsl_end,
   _cogl_pipeline_fragend_glsl_pre_change_notify,
   _cogl_pipeline_fragend_glsl_layer_pre_change_notify
diff --git a/cogl/cogl/driver/gl/cogl-pipeline-opengl.c b/cogl/cogl/driver/gl/cogl-pipeline-opengl.c
index 4ae5bea74..b73eab7e3 100644
--- a/cogl/cogl/driver/gl/cogl-pipeline-opengl.c
+++ b/cogl/cogl/driver/gl/cogl-pipeline-opengl.c
@@ -1173,13 +1173,6 @@ _cogl_pipeline_flush_gl_state (CoglContext *ctx,
       if (G_UNLIKELY (state.error_adding_layer))
         continue;
 
-      if (!state.added_layer)
-        {
-          if (fragend->passthrough &&
-              G_UNLIKELY (!fragend->passthrough (pipeline)))
-            continue;
-        }
-
       if (G_UNLIKELY (!fragend->end (pipeline, pipelines_difference)))
         continue;