Um, Google Chrome doesn't do that, nor can any app. Threads and processes are two different things. Chrome actually does create multiple processes, not multiple threads within the one process.
The reason Chrome is built that way is so that if an application crashes in one tab it won't affect other tabs. Why exactly do you want the user to be able to "kill" parts of your program and what are these parts doing?
I doubt it. It would be possible but I very much doubt it would be easy.I just thought there was an easy way to do it.