senola

(function() {
    /**
     * 记录方法使用情况的类
     * @param {Array.<boolean>} umMap 初始的使用情况
     */
    var UsageManager = function(umMap) {
        this.umMap = umMap || [];
    };
    /**
     * 记录新的使用情况

senola

/**
 * Checkerboard with SVG
 */

background: #eee url('data:image/svg+xml,\
            <svg xmlns="http://www.w3.org/2000/svg" width="100" height="100" fill-opacity=".25" >\
            <rect x="50" width="50" height="50" />\
            <rect y="50" width="50" height="50" />\
            </svg>');
background-size: 30px 30px;

senola

window.requestAnimationFrame =
    window.__requestAnimationFrame ||
        window.requestAnimationFrame ||
        window.webkitRequestAnimationFrame ||
        window.mozRequestAnimationFrame ||
        window.oRequestAnimationFrame ||
        window.msRequestAnimationFrame ||
        (function () {
            return function (callback, element) {
                var lastTime = element.__lastTime;