让IE10等支持classList2.0（转）

chrome24+, firesfox26+起支持classList2.0,即让它同时添加或删除多个类名, toggle方法支持第2个参数，用于强制添加或删除

var div = document.createElement("div");
div.classList.add("a", "b");
if (div.className !== "a b" && window.DOMTokenList) {
    var _add = DOMTokenList.prototype.add;
    DOMTokenList.prototype.add = function() {
        for (var i in arguments) {
            _add.call(this, arguments[i]);
        }
    };
    var _remove = DOMTokenList.prototype.remove;
    DOMTokenList.prototype.remove = function() {
        for (var i in arguments) {
            _remove.call(this, arguments[i]);
        }
    };
    DOMTokenList.prototype.toggle = function(token, forse) {
        token += "";
        var
                result = this.contains(token) , method = result ?
                forse !== true && "remove"  : forse !== false && "add";
        if (method) {
            this[method](token);
        }
        return !result;
    };
}

div.className = "";

div.classList.add("aaa", "ccc");

alert(div.className);