xwayland: pass the X11 display

Pass the X11 display to `meta_xwayland_complete_init()` so that it can
be used without poking into GDK.

https://gitlab.gnome.org/GNOME/mutter/merge_requests/735

src/wayland/meta-xwayland-private.h

@@ -29,7 +29,8 @@ meta_xwayland_init (MetaXWaylandManager *manager,
 		    struct wl_display   *display);
 
 void
-meta_xwayland_complete_init (MetaDisplay *display);
+meta_xwayland_complete_init (MetaDisplay *display,
+                             Display     *xdisplay);
 
 void
 meta_xwayland_shutdown (MetaXWaylandManager *manager);

src/wayland/meta-xwayland.c

@@ -790,7 +790,8 @@ on_x11_display_closing (MetaDisplay *display)
 
 /* To be called right after connecting */
 void
-meta_xwayland_complete_init (MetaDisplay *display)
+meta_xwayland_complete_init (MetaDisplay *display,
+                             Display     *xdisplay)
 {
   MetaWaylandCompositor *compositor = meta_wayland_compositor_get_default ();
   MetaXWaylandManager *manager = &compositor->xwayland_manager;

src/x11/meta-x11-display.c

@@ -1119,14 +1119,13 @@ meta_x11_display_new (MetaDisplay *display, GError **error)
 
   g_assert (prepared_gdk_display);
   gdk_display = g_steal_pointer (&prepared_gdk_display);
+  xdisplay = GDK_DISPLAY_XDISPLAY (gdk_display);
 
 #ifdef HAVE_WAYLAND
   if (meta_is_wayland_compositor ())
-    meta_xwayland_complete_init (display);
+    meta_xwayland_complete_init (display, xdisplay);
 #endif
 
-  xdisplay = GDK_DISPLAY_XDISPLAY (gdk_display);
-
   if (meta_is_syncing ())
     XSynchronize (xdisplay, True);