[mutter] clutter/actor: Pick frame clock of parent if not on any views

[Georges Basile Stavracas Neto <gbsneto src gnome org>]

commit aa34f6ad7cb6b34c08d51ca3b209b938e728fa57
Author: Jonas Ådahl <jadahl gmail com>
Date:   Wed Jun 10 15:05:10 2020 +0200

    clutter/actor: Pick frame clock of parent if not on any views
    
    An actor may be placed without being on any current stage view; in this
    case, to get the ball rolling, walk up the actor tree to find the first
    actor where a frame clock can be picked from.
    
    https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1285

 clutter/clutter/clutter-actor.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)
---
diff --git a/clutter/clutter/clutter-actor.c b/clutter/clutter/clutter-actor.c
index 1c323bc08d..354d36a426 100644
--- a/clutter/clutter/clutter-actor.c
+++ b/clutter/clutter/clutter-actor.c
@@ -16269,11 +16269,20 @@ clutter_actor_peek_stage_views (ClutterActor *self)
 ClutterFrameClock *
 clutter_actor_pick_frame_clock (ClutterActor *self)
 {
+  ClutterActorPrivate *priv = self->priv;
   float max_refresh_rate = 0.0;
   ClutterStageView *best_view = NULL;
   GList *l;
 
-  for (l = self->priv->stage_views; l; l = l->next)
+  if (!priv->stage_views)
+    {
+     if (priv->parent)
+       return clutter_actor_pick_frame_clock (priv->parent);
+     else
+       return NULL;
+    }
+
+  for (l = priv->stage_views; l; l = l->next)
     {
       ClutterStageView *view = l->data;
       float refresh_rate;