This is largely a note to myself, to find later. This has already happened to me several times and I forget how to resolve this every time. The problem is that after some type of system update of one kind or another, Chrome will start causing the X.org server to crash. This sometimes happens immediately on login and sometimes there is a delay before the crash.
The solution? Reinstall the NVIDIA video driver.
This has been my experience with Slackware, I don’t know if other distros run into the same problem.