[gnome-shell] PopupMenuManager: Remove unneeded _owner reference

[Marco Trevisan <marcotrevi src gnome org>]

commit 8c01d341c784516249edef0138c51e99bd9fb3c1
Author: Marco Trevisan (Treviño) <mail 3v1n0 net>
Date:   Wed May 29 14:40:11 2019 -0500

    PopupMenuManager: Remove unneeded _owner reference
    
    Nothing inside PopupMenuManager is using the owner, while a reference of it is
    already owned by the GrabHelper, so remove this dead property.
    
    https://gitlab.gnome.org/GNOME/gnome-shell/merge_requests/565

 js/ui/popupMenu.js | 1 -
 1 file changed, 1 deletion(-)
---
diff --git a/js/ui/popupMenu.js b/js/ui/popupMenu.js
index 305438e47..345934a5f 100644
--- a/js/ui/popupMenu.js
+++ b/js/ui/popupMenu.js
@@ -1215,7 +1215,6 @@ var PopupMenuManager = class {
     constructor(owner, grabParams) {
         grabParams = Params.parse(grabParams,
                                   { actionMode: Shell.ActionMode.POPUP });
-        this._owner = owner;
         this._grabHelper = new GrabHelper.GrabHelper(owner, grabParams);
         this._menus = [];
     }