workspacesView: Calculate the workspaces geometry ourselves

To ensure that we don't recalculate window layouts when zooming
in or out, we need to always pass the full geometry. This will
break window repositioning when we zoom back in; for the purposes
of commit clarity, this breaks this feature for now. It will be
added back soon.

https://bugzilla.gnome.org/show_bug.cgi?id=694469

js/ui/viewSelector.js

@@ -186,6 +186,10 @@ const ViewSelector = new Lang.Class({
             Main.overview.fadeInDesktop();
     },
 
+    setWorkspacesGeometry: function(geom) {
+        this._workspacesDisplay.setWorkspacesGeometry(geom);
+    },
+
     hide: function() {
         this._workspacesDisplay.hide();
     },