[gnome-shell] environment: Replace monkey-patched method with Symbol.iterator

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

commit e20cf1ac78810c8953d41b665a5f66c58e1c0628
Author: Florian Müllner <fmuellner gnome org>
Date:   Tue May 19 21:29:49 2020 +0200

    environment: Replace monkey-patched method with Symbol.iterator
    
    This allows using the actor itself as iterator:
    
      for (let child of container)
          doStuff(child);
    
    https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/1269

 js/ui/environment.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/js/ui/environment.js b/js/ui/environment.js
index 44a92db361..a0b884eb3e 100644
--- a/js/ui/environment.js
+++ b/js/ui/environment.js
@@ -285,7 +285,7 @@ function init() {
         _easeActorProperty(this, 'value', target, params);
     };
 
-    Clutter.Actor.prototype.iterate_children = function* () {
+    Clutter.Actor.prototype[Symbol.iterator] = function* () {
         for (let c = this.get_first_child(); c; c = c.get_next_sibling())
             yield c;
     };