Testing cocoon js RAF

test.js

var me = {};

(function () {
    /**
     * Convert first character of a string to uppercase, if it's a letter.
     * @ignore
     * @function
     * @name capitalize
     * @param  {String} str Input string.
     * @return {String} String with first letter made uppercase.
     */
    var capitalize = function (str) {
        return str.substring(0, 1).toUpperCase() + str.substring(1, str.length);
    };

    /**
     * A collection of utilities to ease porting between different user agents.
     * @namespace me.agent
     * @memberOf me
     */
    me.agent = (function () {
        var api = {};

        /**
         * Known agent vendors
         * @ignore
         */
        var vendors = [ "ms", "MS", "moz", "webkit", "o" ];

        /**
         * Get a vendor-prefixed property
         * @public
         * @name prefixed
         * @function
         * @param {String} name Property name
         * @param {Object} [obj=window] Object or element reference to access
         * @return {Mixed} Value of property
         * @memberOf me.agent
         */
        api.prefixed = function (name, obj) {
            obj = obj || window;
            if (name in obj) {
                return obj[name];
            }

            var uc_name = capitalize(name);

            var result;
            vendors.some(function (vendor) {
                var name = vendor + uc_name;
                return (result = (name in obj) ? obj[name] : undefined);
            });
            return result;
        };

        /**
         * Set a vendor-prefixed property
         * @public
         * @name setPrefixed
         * @function
         * @param {String} name Property name
         * @param {Mixed} value Property value
         * @param {Object} [obj=window] Object or element reference to access
         * @memberOf me.agent
         */
        api.setPrefixed = function (name, value, obj) {
            obj = obj || window;
            if (name in obj) {
                obj[name] = value;
                return;
            }

            var uc_name = capitalize(name);

            vendors.some(function (vendor) {
                var name = vendor + uc_name;
                if (name in obj) {
                    obj[name] = value;
                    return true;
                }
                return false;
            });
        };

        return api;
    })();
})();

var parent = document.getElementById("screen");

var canvas = document.createElement("canvas");
canvas.width = 1136;
canvas.height = 640;
var ctx = canvas.getContext("2d");

parent.appendChild(canvas);

window.requestAnimationFrame = me.agent.prefixed('requestAnimationFrame');

function render () {
  requestAnimationFrame(render);

  ctx.clearRect(0, 0, 1136, 640);
  ctx.fillStyle = '#ff0';
  ctx.fillRect(50, 50, 250, 250);
}

render();