Pull-to-refresh is a common UI paradigm in mobile applications, but it's currently not possible to implement it well in any mobile browser. Talking offline with Benjamin it sounds like there's interest in (and already work happening for) enabling such scenarios. I've got a survey of common p2r effects and platform support as well as some ideas for chromium here: https://docs.google.com/a/chromium.org/document/d/1cBYKZMCeeaT6pN3VYu9uox8AXbJKmOaEmpL4BTg5lT4/edit#. I expect WebKit will want to make a different set of tradeoffs, but hopefully the scenarios and pointers to other implementations are still useful. Blink works to enable such scenarios are tracked by http://crbug.com/328503.