[gtk/nielsdg/gsk-gl-renderer-assertion] gsk: Document gsk_renderer_realize()

[Niels De Graef <nielsdg src gnome org>]

commit e566ba54d980a362cdb1d947b71f7bff89369096
Author: Niels De Graef <nielsdegraef gmail com>
Date:   Tue Jan 11 10:04:16 2022 +0100

    gsk: Document gsk_renderer_realize()
    
    Document the return value and more importantly, specify that a call to
    `gsk_renderer_realize()` needs to be matched with a call
    `gsk_renderer_unrealize()`.
    
    Prevents issues like https://gitlab.gnome.org/GNOME/gtk/-/issues/4625

 gsk/gskrenderer.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)
---
diff --git a/gsk/gskrenderer.c b/gsk/gskrenderer.c
index ff4ff976ce..b782cfd493 100644
--- a/gsk/gskrenderer.c
+++ b/gsk/gskrenderer.c
@@ -289,10 +289,15 @@ gsk_renderer_is_realized (GskRenderer *renderer)
  *
  * Since GTK 4.6, the surface may be `NULL`, which allows using
  * renderers without having to create a surface.
+ *
+ * Note that it is mandatory to call [method@Gsk.Renderer.unrealize] before
+ * destroying the renderer.
+ *
+ * Returns: Whether the renderer was successfully realized
  */
 gboolean
 gsk_renderer_realize (GskRenderer  *renderer,
-                      GdkSurface    *surface,
+                      GdkSurface   *surface,
                       GError      **error)
 {
   GskRendererPrivate *priv = gsk_renderer_get_instance_private (renderer);