Webview not displaying in MacOS using Delphi XE2

Getting the NSWindow of a FMX form
convert a TForm reference to a NSWindow
set Host Window.
MyWebView.setHostWindow(MyNSWindow)

procedure TForm2.Button1Click(Sender: TObject);
var
[...]
 ObjTOC: TOCLocal;
 MyNSWindow : NSWindow;
[...]  
 ObjTOC := (FmxHandleToObjC(Form2.Handle) as TOCLocal);
 MyNSWindow := NSWindow(TOCLocalAccess(ObjTOC).Super);

PWebView := TWebView.Alloc.initWithFrame(MakeNSRect(10, 10, 300, 300), nil, nil);
 MyWebView := TWebView.Wrap(PWebView);
 MyWebView.setHostWindow(MyNSWindow);

[...]
 MyWebView.mainFrame.loadRequest(urlreq);
end;