Umbraco - Render .Net User Control (ascx) macro with Razor

UmbracoMacro.cshtml

@*
  Render Umbraco macro from within Razor macro
  http://stackoverflow.com/questions/10689284/umbraco-render-net-user-control-ascx-macro-with-razor
  Yes, it looks like a server control but it does work from a Razor macro.
  The example below is for rendering a Contour form
*@

<umbraco:Macro runat="server" language="cshtml">
	@{
		var writer = new HtmlTextWriter(Output);
		var navigation = new umbraco.presentation.templateControls.Macro();

		navigation.Alias = "umbracoContour.RazorRenderForm";
		navigation.MacroAttributes.Add("formguid", "FORM-GUID-HERE");

		navigation.RenderControl(writer);
	}
</umbraco:Macro>