Comment 4 for bug 1389777

I'm keeping this bug focused specifically on the speed at which flings decelerate, which I've improved significantly on trunk (with a bit of trial and error, so it could still probably be improved).

As for the other issues:

- The addressbar issues are covered by bug 1370366 (the renderer compositor will calculate the header position, as it does on Chrome Android)
- I'm aware of the jumpy scrolling. I'm not sure what's causing it yet, but it does seem to be Krillin specific