How do I build a pdf file/blob from byte[] via a AJAX / REST call

Question: I have WebMethod as illustrated below that should return a byte[]. The byte[] then needs to be retrieved by AJAX call and display the pdf file.
[WebMethod]public static byte[] GeneratePDF()
{    var pdfPath = Path.Combine(System.Web.Hosting.HostingEnvironment.MapPath("~/PDFTemplates/W9.pdf"));    PdfReader pdfReader = new PdfReader(pdfPath);    MemoryStream stream = new MemoryStream();    PdfStamper stamper = new PdfStamper(pdfReader, stream);    pdfReader.Close();    stamper.Close();    stream.Flush();    stream.Close();        byte[] bytes = System.IO.File.ReadAllBytes(pdfPath);        return bytes;            
}
Note: for AJAX call, I have following AngularJS code
function GeneratePDF() {$http.post('/Default.aspx/GeneratePDF', '', { responseType: 'arraybuffer' }).then(function (response) {

		var blob = new Blob([new Uint8Array(response.data)], { type: 'application/pdf' });
		$scope.url = (window.URL || window.webkitURL).createObjectURL(blob);
		window.open($scope.url);		
	});
}
And html anchor below for downloading pdf file