[gnome-shell] workspace: Use graphene instead of clutter

[Florian Müllner <fmuellner src gnome org>]

commit a144a1c76da06db8b33434db3c05400a76da34a4
Author: Robert Mader <robert mader posteo de>
Date:   Thu Oct 17 11:22:30 2019 +0200

    workspace: Use graphene instead of clutter
    
    This was forgotten after the graphene type port landed.
    
    https://gitlab.gnome.org/GNOME/gnome-shell/merge_requests/770

 js/ui/workspace.js | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)
---
diff --git a/js/ui/workspace.js b/js/ui/workspace.js
index acad9eaf70..dc4c212b32 100644
--- a/js/ui/workspace.js
+++ b/js/ui/workspace.js
@@ -1,7 +1,8 @@
 // -*- mode: js; js-indent-level: 4; indent-tabs-mode: nil -*-
 /* exported Workspace */
 
-const { Atk, Clutter, GLib, GObject, Meta, Pango, Shell, St } = imports.gi;
+const { Atk, Clutter, GLib, GObject,
+        Graphene, Meta, Pango, Shell, St } = imports.gi;
 const Signals = imports.signals;
 
 const DND = imports.ui.dnd;
@@ -301,7 +302,7 @@ var WindowClone = GObject.registerClass({
 
     _computeWindowCenter() {
         let box = this.realWindow.get_allocation_box();
-        this._windowCenter = new Clutter.Point({
+        this._windowCenter = new Graphene.Point({
             x: box.get_x() + box.get_width() / 2,
             y: box.get_y() + box.get_height() / 2,
         });