#iframe-wrap {
position: fixed;
top: 100px;
bottom: 0px;
left: 0px;
right: 0px;
-webkit-overflow-scrolling: touch;
overflow-y: scroll;
}
#iframe-wrap iframe {
border: none;
100%;
height: 101%;
}
<div id="iframe-wrap">
<iframe src="">
</iframe>
</div>