We should support rubber-banding in sub-frames.
Created attachment 237918 [details]
Though there are some small changes in 2 latching test results, I don't think that this patch changes any of the latching behaviors. That being said, it does seem like latching is a little broken on TOT right now with iframes. Specifically, if you start a momentum scroll gesture in an iframe then right now in TOT, if the gesture is strong enough, the main frame will start scrolling as a part of that same gesture once you reach the end of the subframe. That shouldn't happen. Again, not a regression with this patch, just something we should fix. But in other cases (it's not a momentum gesture, or the main frame isn't scrollable) you get the correct rubber-banding behavior.
I filed https://bugs.webkit.org/show_bug.cgi?id=136729 for the existing latching bug.
Thanks Tim! http://trac.webkit.org/changeset/173523