Right now, all our input metrics are per input - i.e., per scroll, per scroll update, per key press, etc. Ideally we'd have some metrics that normalized these per page, or per touch sequence.

We should brainstorm on this at some point, but here are a few ideas:
- The worst scroll update per touch sequence.
- The worst scroll start per page view.
- The worst scroll update per page view.
- The worst key press per page view.