[gtk/wip/chergert/macos-iosurface] add note about needs display

[Christian Hergert <chergert src gnome org>]

commit 07df32e0d1af7d96cf791e3e9a408906245b3ab7
Author: Christian Hergert <christian hergert me>
Date:   Fri Feb 11 17:09:24 2022 -0800

    add note about needs display

 gdk/macos/GdkMacosView.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)
---
diff --git a/gdk/macos/GdkMacosView.c b/gdk/macos/GdkMacosView.c
index 52a55a7cef..ee60201e76 100644
--- a/gdk/macos/GdkMacosView.c
+++ b/gdk/macos/GdkMacosView.c
@@ -81,6 +81,18 @@
     }
 
   [(GdkMacosLayer *)[self layer] swapBuffer:buffer withDamage:damage];
+
+#if 0
+  /* This doesn't seem to be necessary */
+  guint n_rects = cairo_region_num_rectangles (damage);
+  for (guint i = 0; i < n_rects; i++)
+    {
+      cairo_rectangle_int_t rect;
+
+      cairo_region_get_rectangle (damage, i, &rect);
+      [self setNeedsDisplayInRect:NSMakeRect (rect.x, rect.y, rect.width, rect.height)];
+    }
+#endif
 }
 
 @end