I got a new Moto X over the break, and I noticed that the browser scrolling performance was beyond terrible. Every major website I went to and try to scroll would stutter along. Then I remembered that I'd installed the beta version of 1Password for Android and turned on filling. Turned filling off: browser scrolling now buttery smooth. Turned it back on: back to scrolling janky.
I haven't looked into how those APIs work on Lollipop but it seems like maybe some 1Password code is running on browser scroll? If so it would be awesome to know if you've noticed this too or if you're looking into it? My browser is just the store version of Chrome, running on a 2014 Moto X, Android 5.0.