[mutter] compositor: Remove dead code: META_DISABLE_MIPMAPS

[Jonas Ådahl <jadahl src gnome org>]

commit 04e411c2c0604ef54a1fe64f2b718d37028b404f
Author: Daniel van Vugt <daniel van vugt canonical com>
Date:   Tue Jul 3 15:15:54 2018 +0800

    compositor: Remove dead code: META_DISABLE_MIPMAPS
    
    Seems to have been unused for quite some time.

 src/compositor/compositor-private.h | 1 -
 src/compositor/compositor.c         | 3 ---
 2 files changed, 4 deletions(-)
---
diff --git a/src/compositor/compositor-private.h b/src/compositor/compositor-private.h
index 40c0344cc..125a0afe8 100644
--- a/src/compositor/compositor-private.h
+++ b/src/compositor/compositor-private.h
@@ -22,7 +22,6 @@ struct _MetaCompositor
   gint64          server_time_offset;
 
   guint           server_time_is_monotonic_time : 1;
-  guint           no_mipmaps  : 1;
 
   ClutterActor          *stage, *window_group, *top_window_group, *feedback_group;
   ClutterActor          *background_actor;
diff --git a/src/compositor/compositor.c b/src/compositor/compositor.c
index 8c924d256..6c6708792 100644
--- a/src/compositor/compositor.c
+++ b/src/compositor/compositor.c
@@ -1241,9 +1241,6 @@ meta_compositor_new (MetaDisplay *display)
   compositor->display = display;
   compositor->context = clutter_backend->cogl_context;
 
-  if (g_getenv("META_DISABLE_MIPMAPS"))
-    compositor->no_mipmaps = TRUE;
-
   g_signal_connect (meta_shadow_factory_get_default (),
                     "changed",
                     G_CALLBACK (on_shadow_factory_changed),