update

@@ -160,48 +160,6 @@ $header.on('touchstart', 'a', function() {
     $(this).removeClass('highlight');
 });
 
-(function() {
-    var lastTime = 0;
-    var prefixes = 'webkit moz ms o'.split(' ');
-
-    var requestAnimationFrame = window.requestAnimationFrame;
-    var cancelAnimationFrame = window.cancelAnimationFrame;
-
-    var prefix;
-
-    //通过遍历各浏览器前缀，来得到requestAnimationFrame和cancelAnimationFrame在当前浏览器的实现形式
-    for( var i = 0; i < prefixes.length; i++ ) {
-        if ( requestAnimationFrame && cancelAnimationFrame ) {
-            break;
-        }
-        prefix = prefixes[i];
-        requestAnimationFrame = requestAnimationFrame || window[ prefix + 'RequestAnimationFrame' ];
-        cancelAnimationFrame  = cancelAnimationFrame  || window[ prefix + 'CancelAnimationFrame' ] || window[ prefix + 'CancelRequestAnimationFrame' ];
-    }
-
-    //如果当前浏览器不支持requestAnimationFrame和cancelAnimationFrame，则会退到setTimeout
-    if ( !requestAnimationFrame || !cancelAnimationFrame ) {
-        requestAnimationFrame = function( callback, element ) {
-            var currTime = new Date().getTime();
-
-            //为了使setTimteout的尽可能的接近每秒60帧的效果
-            var timeToCall = Math.max( 0, 16 - ( currTime - lastTime ) );
-            var id = window.setTimeout( function() {
-                callback( currTime + timeToCall );
-            }, timeToCall );
-            lastTime = currTime + timeToCall;
-            return id;
-        };
-
-        cancelAnimationFrame = function( id ) {
-            window.clearTimeout( id );
-        };
-    }
-
-    window.requestAnimationFrame = requestAnimationFrame;
-    window.cancelAnimationFrame = cancelAnimationFrame;
-}());
-
 //暴露公共接口
 window.cookie = cookie;