[gtk/wip/chergert/quartz4u] macos: use image surface for backing

[Christian Hergert <chergert src gnome org>]

commit a66f3991443f04edbff5f09ffc80d9f0eab0503a
Author: Christian Hergert <chergert redhat com>
Date:   Tue May 5 18:02:22 2020 -0700

    macos: use image surface for backing

 gdk/macos/gdkmacoscairocontext.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/gdk/macos/gdkmacoscairocontext.c b/gdk/macos/gdkmacoscairocontext.c
index e758a682f2..3cdfce078f 100644
--- a/gdk/macos/gdkmacoscairocontext.c
+++ b/gdk/macos/gdkmacoscairocontext.c
@@ -60,7 +60,7 @@ create_cairo_surface_for_surface (GdkSurface *surface)
   width = scale * gdk_surface_get_width (surface);
   height = scale * gdk_surface_get_height (surface);
 
-  cairo_surface = cairo_quartz_surface_create_for_cg_context (cg, width, height);
+  cairo_surface = cairo_image_surface_create (CAIRO_FORMAT_ARGB32, width, height);
 
   if (cairo_surface != NULL)
     cairo_surface_set_device_scale (cairo_surface, scale, scale);