[mutter] Stop including core.h where it's not used

[Florian Müllner <fmuellner src gnome org>]

commit c474ad6a53b0b28d97225f7c97eec9506c732d5c
Author: Jonas Ådahl <jadahl gmail com>
Date:   Thu Aug 29 20:57:27 2019 +0300

    Stop including core.h where it's not used
    
    It provides glue for window frame controls and internal window
    management, and that is only relevant for a couple of places in src/ui/.
    
    https://gitlab.gnome.org/GNOME/mutter/merge_requests/854

 src/compositor/compositor.c | 1 -
 src/core/window.c           | 1 -
 src/x11/window-x11.c        | 1 -
 3 files changed, 3 deletions(-)
---
diff --git a/src/compositor/compositor.c b/src/compositor/compositor.c
index d4b6d14c3..f7dcbd579 100644
--- a/src/compositor/compositor.c
+++ b/src/compositor/compositor.c
@@ -66,7 +66,6 @@
 #include "compositor/meta-window-actor-wayland.h"
 #include "compositor/meta-window-actor-private.h"
 #include "compositor/meta-window-group-private.h"
-#include "core/core.h"
 #include "core/display-private.h"
 #include "core/frame.h"
 #include "core/util-private.h"
diff --git a/src/core/window.c b/src/core/window.c
index e276b1e59..850ee21cc 100644
--- a/src/core/window.c
+++ b/src/core/window.c
@@ -70,7 +70,6 @@
 #include "cogl/cogl-trace.h"
 #include "core/boxes-private.h"
 #include "core/constraints.h"
-#include "core/core.h"
 #include "core/edge-resistance.h"
 #include "core/frame.h"
 #include "core/keybindings-private.h"
diff --git a/src/x11/window-x11.c b/src/x11/window-x11.c
index 31635a2f5..29f047257 100644
--- a/src/x11/window-x11.c
+++ b/src/x11/window-x11.c
@@ -36,7 +36,6 @@
 #include "backends/meta-logical-monitor.h"
 #include "backends/x11/meta-backend-x11.h"
 #include "core/boxes-private.h"
-#include "core/core.h"
 #include "core/frame.h"
 #include "core/meta-workspace-manager-private.h"
 #include "core/window-private.h"