[LayaAirIDE 1.0]Mac下LayaAirIDE1.7.20版本声音预加载失败，但windows下同个版本加载正常

Mac下的AS3代码如下：
 
private function init():void
{
        var assetArr:Array=[
            {url:"res/sound/music_gameplay.mp3", type:Loader.SOUND},
            {url:"res/sound/button.mp3", type:Loader.SOUND},
            {url:"res/sound/mob_true.mp3", type:Loader.SOUND},
            {url:"res/sound/mob_hit.mp3", type:Loader.SOUND},
            {url:"res/sound/star_pick.mp3", type:Loader.SOUND},
            {url:"res/sound/start_explode.mp3", type:Loader.SOUND}
        ];

        Laya.loader.load(assetArr,Handler.create(this,onComplete),Handler.create(this,onProgress));
}

private function onProgress(loadNum:Number):void
{
}
 

private function onComplete():void
{
}