[metacity] compositor-xrender: create root tile in pre_paint

[Alberts Muktupāvels <muktupavels src gnome org>]

commit 3a80f1a3a0993d1e732adfb258bb25c52b67363e
Author: Alberts Muktupāvels <alberts muktupavels gmail com>
Date:   Sun Oct 20 15:10:12 2019 +0300

    compositor-xrender: create root tile in pre_paint

 src/compositor/meta-compositor-xrender.c | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)
---
diff --git a/src/compositor/meta-compositor-xrender.c b/src/compositor/meta-compositor-xrender.c
index 11164985..cb144cab 100644
--- a/src/compositor/meta-compositor-xrender.c
+++ b/src/compositor/meta-compositor-xrender.c
@@ -811,12 +811,7 @@ paint_root (MetaCompositorXRender *xrender,
   int width, height;
 
   g_return_if_fail (root_buffer != None);
-
-  if (xrender->root_tile == None)
-    {
-      xrender->root_tile = root_tile (xrender->screen);
-      g_return_if_fail (xrender->root_tile != None);
-    }
+  g_return_if_fail (xrender->root_tile != None);
 
   meta_screen_get_size (xrender->screen, &width, &height);
   XRenderComposite (xrender->xdisplay, PictOpSrc,
@@ -1617,6 +1612,9 @@ meta_compositor_xrender_pre_paint (MetaCompositor *compositor)
   if (xrender->root_buffer == None)
     xrender->root_buffer = create_root_buffer (xrender);
 
+  if (xrender->root_tile == None)
+    xrender->root_tile = root_tile (xrender->screen);
+
   META_COMPOSITOR_CLASS (meta_compositor_xrender_parent_class)->pre_paint (compositor);
 
   stack = meta_compositor_get_stack (compositor);