[metacity/gnome-3-18] compositor: use correct xid when removing window

[Alberts Muktupāvels <muktupavels src gnome org>]

commit 0aa6e7ea3a50830af03a4294ad9156f53ced8f7f
Author: Alberts Muktupāvels <alberts muktupavels gmail com>
Date:   Thu Apr 14 19:38:00 2016 +0300

    compositor: use correct xid when removing window

 src/compositor/compositor-xrender.c |    8 +++++++-
 1 files changed, 7 insertions(+), 1 deletions(-)
---
diff --git a/src/compositor/compositor-xrender.c b/src/compositor/compositor-xrender.c
index 3e1eb5e..5b34d5f 100644
--- a/src/compositor/compositor-xrender.c
+++ b/src/compositor/compositor-xrender.c
@@ -2864,10 +2864,16 @@ xrender_free_window (MetaCompositor *compositor,
 {
 #ifdef HAVE_COMPOSITE_EXTENSIONS
   MetaCompositorXRender *xrc;
+  MetaFrame *frame;
   Window xwindow;
 
   xrc = (MetaCompositorXRender *) compositor;
-  xwindow = meta_window_get_xwindow (window);
+  frame = meta_window_get_frame (window);
+
+  if (frame)
+    xwindow = meta_frame_get_xwindow (frame);
+  else
+    xwindow = meta_window_get_xwindow (window);
 
   destroy_win (xrc->display, xwindow, FALSE);
 #endif