When the compositor is scrolling the page, the web-page might be running a bunch of scripts, which can affect the smoothness of the scroll. It may be possible to throttle some of these scripts during the scroll, more details at [1]. But first, we should collect some metrics to see how big of a problem this is.

[1] https://docs.google.com/document/d/1VOd9cTJVsWRCthzLQ9TEbw08oIhpgphs5_BKrhSRfOE/edit#heading=h.x597b29yj0hi