Chrome App webview and touch scroll propagation
Solution 1:
I'm going to assume a couple things here: Styling a Chrome app is similar to styling a webpage. Your current scrolling solution relies on using overflow:hidden and using JavaScript only to scroll.
I fixed something similar once for a page. Its strange but I learned that for touch devices, a scrollbar is invisible unless the user interacts with it. If you change the style to overflow-x: scroll...a scrollbar will appear (and you'll need to deal with that later for desktop with Modernizr or some similar way to detect touch enabled device). Then comment out your scrolling code (temporarily of course because you'll need it for non-touch). If it scrolls fine with the overflow change and the scrolipt change then all you need to do next is to detect touch and conditionally turn on the script and change overflow appropriately.