title: Prevent grey overlay on touchstart in mobile Safari/Webview
body: <p>I am building an iOS app in webkit, so my whole UI is a webview. on touchStart of any element near the outer boundary of the webview (that does not have a touchStart event bound to it), I get a translucent grey box overlay the full area of the webview. I've eliminated <code>-webkit-tap-highlight-color</code> or <code>-webkit-touch-callout</code> as causes. What do I do to remove this behavior?</p>