[gnome-shell] layout: Fix an accidental undefined variable error

[Jasper St. Pierre <jstpierre src gnome org>]

commit 651030ba939cae0762953560274dfa297c758cf0
Author: Jasper St. Pierre <jstpierre mecheye net>
Date:   Tue Mar 27 15:08:54 2012 -0300

    layout: Fix an accidental undefined variable error
    
    The layout code was using actorData without defining it first.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=673189

 js/ui/layout.js |    7 +++++--
 1 files changed, 5 insertions(+), 2 deletions(-)
---
diff --git a/js/ui/layout.js b/js/ui/layout.js
index d66437e..c399d42 100644
--- a/js/ui/layout.js
+++ b/js/ui/layout.js
@@ -781,10 +781,13 @@ const Chrome = new Lang.Class({
 
     _actorReparented: function(actor, oldParent) {
         let newParent = actor.get_parent();
-        if (!newParent)
+        if (!newParent) {
             this._untrackActor(actor);
-        else
+        } else {
+            let i = this._findActor(actor);
+            let actorData = this._trackedActors[i];
             actorData.isToplevel = (newParent == Main.uiGroup);
+        }
     },
 
     _updateVisibility: function() {