How does the renderer read/access user settings?

[Ben Amsalem]

I wonder how the renderer gets the user settings information he needs to "make decisions". 

For example: when a new window(or tab) is about to be opened, under the same thread (with `window.open`), sometimes there is a popups blocker that shows up. I can be disabled if you allow popups and/or add the domain to the whitelist. So, how the renderer gets this user settings information? (I guess it's loaded to memory it can access...)

Can you give some overview of the process of reading those settings? Code examples? References to areas in the source code?