[gnome-shell/wjt/references-to-undefined-properties] workspacesView: initialize self._restackedNotifyId

[Will Thompson <wjt src gnome org>]

commit b2fabd935637126e7a8d00b11f918776e742280a
Author: Will Thompson <will willthompson co uk>
Date:   Tue Sep 25 23:00:53 2018 +0100

    workspacesView: initialize self._restackedNotifyId
    
    This attribute was previously only assigned in show(). hide() compares
    this attribute to 0. If hide() is called before show() is first called,
    the comparison would give the correct result (undefined > 0 is false)
    but log a warning:
    
        JS WARNING: [resource:///org/gnome/shell/ui/workspacesView.js 529]:
        reference to undefined property "_restackedNotifyId"
    
    Initialize this attribute in _init(), alongside _scrollEventId and
    _keyPressEventId which are also used in hide().

 js/ui/workspacesView.js | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/js/ui/workspacesView.js b/js/ui/workspacesView.js
index 4ba8db754..4c97094aa 100644
--- a/js/ui/workspacesView.js
+++ b/js/ui/workspacesView.js
@@ -481,6 +481,7 @@ var WorkspacesDisplay = new Lang.Class({
         this._switchWorkspaceNotifyId = 0;
 
         this._notifyOpacityId = 0;
+        this._restackedNotifyId = 0;
         this._scrollEventId = 0;
         this._keyPressEventId = 0;