[gtk/x11-resize] x11: Update surface size for popups too

[Matthias Clasen <matthiasc src gnome org>]

commit 8010bc45968668b62a77b5866863c3e077935bef
Author: Matthias Clasen <mclasen redhat com>
Date:   Fri Mar 13 21:33:23 2020 -0400

    x11: Update surface size for popups too
    
    Without this, the back buffers of the wrong size
    keep being used, causing flickery misdraws, as
    seen when expanding the expander in the popover
    in widget-factory.

 gdk/x11/gdksurface-x11.c | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/gdk/x11/gdksurface-x11.c b/gdk/x11/gdksurface-x11.c
index b9e122a91a..9a1b71698e 100644
--- a/gdk/x11/gdksurface-x11.c
+++ b/gdk/x11/gdksurface-x11.c
@@ -1319,6 +1319,7 @@ x11_surface_resize (GdkSurface *surface,
       impl->unscaled_height = height * impl->surface_scale;
       surface->width = width;
       surface->height = height;
+      _gdk_surface_update_size (surface);
       _gdk_x11_surface_update_size (GDK_X11_SURFACE (surface));
     }
   else