I've gotten this to work and it does what I want, close tabs that are old, unvisited. However, getting it to start is quite tricky, and I have a million tabs ripe for auto close, yet auto close has not started to work yet.

This is a good!
I want to disable to display the popup dialog that is appeared when a tab has been closed.
It will be help me.

good idea, but would be better if you can whitelist tabs with custom domains. Do not close tabs on which x.y URL/ domain opened.