Extending Chrome to capture Mouse Data on Browser

The idea was simple. Take the mouse data during general use, and store it into a local database. However, then I learned, sadly that you cannot use php! Is there any way to, with chrome, to capture window data, such as mouse locations, click locations, and so forth?

I want to simply store event.clientX and event.clientY paired together in some sort of file.

In short, I want it to work the same way it'd work on a single web page if you used the onmousemove event.

Can anyone help explain if this is possible, and a point in the right direction? If it isn't possible, let me know why.