if (!(Date.now && Date.prototype.getTime)) { 
Date.now = function now(){ 
return new Date().getTime(); 
} 
; 
} 
if (!(global.performance && global.performance.now)) { 
var startTime = Date.now(); 
if (!global.performance) { 
global.performance = { 
}
; 
} 
global.performance.now = function (){ 
return Date.now() - startTime; 
} 
; 
} 
var lastTime = Date.now(); 
var vendors = ['ms', 'moz', 'webkit', 'o'] ; 
for (var x = 0; 
x < _AN_Read_length('length', vendors) && !global.requestAnimationFrame; ++x){ 
global.requestAnimationFrame = global[vendors[x] + 'RequestAnimationFrame']; 
global.cancelAnimationFrame = global[vendors[x] + 'CancelAnimationFrame'] || global[vendors[x] + 'CancelRequestAnimationFrame']; 
} 
if (!global.requestAnimationFrame) { 
global.requestAnimationFrame = function (callback){ 
if (typeof callback !== 'function') { 
throw new TypeError(callback + 'is not a function')
} 
var currentTime = Date.now(), delay = 16 + lastTime - currentTime; 
if (delay < 0) { 
delay = 0; 
} 
lastTime = currentTime; 
return _AN_Call_settimeout('setTimeout', window, function (){ 
lastTime = Date.now(); 
callback(performance.now()); 
} 
, delay); 
} 
; 
} 
if (!global.cancelAnimationFrame) { 
global.cancelAnimationFrame = function (id){ 
clearTimeout(id); 
} 
; 
}