When you set `overscroll-behavior` to a value other than `auto`, the browser should not perform scroll chaining. We respect this for mouse or touch scrolling, however keyboard scrolls were ignoring it. This change makes keyboard scrolling respect overscroll-behavior as well.
Using overscroll-behavior helps authors avoid user confusion when scrolling in components that feel disconnected from their ancestor scrolling. By preventing non-local side effects, it provides a more predictable experience.
Samples: https://jsfiddle.net/qy78w5ga