ionic v1.2取消了ion-content默认的阻尼回弹效果，官方博客的评论里有解释：
Great news, thank you! It seems that the “has-bouncing=’true'” does not work with the native scroll, is it correct? I managed though to have it again by going to back go js scroll (overflow-scroll=”false”)
I only checked in the browser so if any one can confirm that with native scrolling removes bouncing that would be great.
I need this feature for a custom ‘pull refresh’ method I had.
也就是说，v1.2之后想要有阻尼回弹效果，需要这么做：
<ion-content overflow-scroll="false" has-bouncing="true"></ion-content>
