[gnome-shell/gnome-3-28] workspacesView: initialize self._restackedNotifyId

[Florian Müllner <fmuellner src gnome org>]

commit 06c6ecc15b3a32c53a0012134e7a898de62827bc
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().
    
    (cherry picked from commit b2fabd935637126e7a8d00b11f918776e742280a)

 js/ui/workspacesView.js | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/js/ui/workspacesView.js b/js/ui/workspacesView.js
index 563e43da4..bb7835c0e 100644
--- a/js/ui/workspacesView.js
+++ b/js/ui/workspacesView.js
@@ -470,6 +470,7 @@ var WorkspacesDisplay = new Lang.Class({
         this._switchWorkspaceNotifyId = 0;
 
         this._notifyOpacityId = 0;
+        this._restackedNotifyId = 0;
         this._scrollEventId = 0;
         this._keyPressEventId = 0;