[gnome-flashback] common: remove gf_background_surface_get_average_color

[Alberts Muktupāvels <muktupavels src gnome org>]

commit 7a8d437c96e08f4916072bb4fe4d209a57bf8258
Author: Alberts Muktupāvels <alberts muktupavels gmail com>
Date:   Sat Mar 20 17:40:33 2021 +0200

    common: remove gf_background_surface_get_average_color

 gnome-flashback/libcommon/gf-background-utils.c | 6 ------
 gnome-flashback/libcommon/gf-background-utils.h | 2 --
 2 files changed, 8 deletions(-)
---
diff --git a/gnome-flashback/libcommon/gf-background-utils.c b/gnome-flashback/libcommon/gf-background-utils.c
index 927871a..4c093ee 100644
--- a/gnome-flashback/libcommon/gf-background-utils.c
+++ b/gnome-flashback/libcommon/gf-background-utils.c
@@ -358,9 +358,3 @@ gf_background_surface_set_as_root (GdkDisplay      *display,
 
   gdk_x11_display_ungrab (display);
 }
-
-GdkRGBA *
-gf_background_surface_get_average_color (cairo_surface_t *surface)
-{
-  return cairo_surface_get_user_data (surface, &average_color_key);
-}
diff --git a/gnome-flashback/libcommon/gf-background-utils.h b/gnome-flashback/libcommon/gf-background-utils.h
index cd91acc..e84e4a0 100644
--- a/gnome-flashback/libcommon/gf-background-utils.h
+++ b/gnome-flashback/libcommon/gf-background-utils.h
@@ -29,8 +29,6 @@ cairo_surface_t *gf_background_surface_get_from_root     (GdkDisplay      *displ
 void             gf_background_surface_set_as_root       (GdkDisplay      *display,
                                                           cairo_surface_t *surface);
 
-GdkRGBA         *gf_background_surface_get_average_color (cairo_surface_t *surface);
-
 G_END_DECLS
 
 #endif