WordPress 3.5 : How to allow PDF/ICO file upload in media uploader

Hello,

I have created a theme and added icon (.ico file) upload feature so anyone can select icon file for Favicon. The old code works perfectly.

But after updating to WP 3.5, I updated my old code with this new one:

jQuery(document).ready(function($){
var _custom_media = true,
_orig_send_attachment = wp.media.editor.send.attachment;
$("#myupload_button").click(function(e) {
var send_attachment_bkp = wp.media.editor.send.attachment;
var button = $(this);
var id = button.attr("id").replace("_button", "");
_custom_media = true;
wp.media.editor.send.attachment = function(props, attachment){
if ( _custom_media ) {
$("#"+id).val(attachment.url);
} else {
return _orig_send_attachment.apply( this, [props, attachment] );
};
}
wp.media.editor.open(button);
return false;
});
$(".add_media").on("click", function(){
_custom_media = false;
});
});

But not it doesn’t allow me to upload ICO file and only allow me to upload PNG/JPG imgages.

I want to upload ICO file and than want to get ICO file URL in a textarea.

So how can I configure to upload ICO file too?