Daniel Gatti's script to allow tab scrolling by placing cursor on tab bar, and scrolling mouse wheel. In Windows, I pin it to the taskbar and run it once after opening Chrome. It works flawlessly. There is a comment on one of the chrome problem blogs about how great it is. It used to be available on Google + which sadly is no more. I have NOT reviewed the code, though 2 years ago people said they had, and found no problems. Use at your own risk.
I'm posting this as a public service because nothing else seems to work as well, and people have complained recently (Jan-June 2019) that Chrome suddenly scrolls tabs uncontrollably. I have not had this problem; I do NOT know if mousewheeltabscroll4chrome is why.
If Daniel wants to claim this project, I would welcome that. As I recall, he had posted it as freeware.