[mutter/wip/lantw/fix-build-when-native-backend-is-disabled] wayland/pointer-constraints: Fix build when native backend is disabled

[Ting-Wei Lan <lantw src gnome org>]

commit 46ef8fea8d564918ace1f9611d82fa630f9ae09f
Author: Ting-Wei Lan <lantw src gnome org>
Date:   Sat Jun 22 21:23:19 2019 +0800

    wayland/pointer-constraints: Fix build when native backend is disabled
    
    https://gitlab.gnome.org/GNOME/mutter/merge_requests/636

 src/wayland/meta-wayland-pointer-constraints.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)
---
diff --git a/src/wayland/meta-wayland-pointer-constraints.c b/src/wayland/meta-wayland-pointer-constraints.c
index aa59dbcb4..22197d58d 100644
--- a/src/wayland/meta-wayland-pointer-constraints.c
+++ b/src/wayland/meta-wayland-pointer-constraints.c
@@ -30,7 +30,6 @@
 
 #include "backends/meta-backend-private.h"
 #include "backends/meta-pointer-constraint.h"
-#include "backends/native/meta-backend-native.h"
 #include "core/frame.h"
 #include "core/window-private.h"
 #include "meta/meta-backend.h"
@@ -45,6 +44,10 @@
 
 #include "pointer-constraints-unstable-v1-server-protocol.h"
 
+#ifdef HAVE_NATIVE_BACKEND
+#include "backends/native/meta-backend-native.h"
+#endif
+
 static GQuark quark_pending_constraint_state = 0;
 static GQuark quark_surface_pointer_constraints_data = 0;