For Google Chrome:
~ is your home directory) should be sufficient. Why don't you try it and see? (Of course, this will delete all your bookmarks too.)
If that's not sufficient, you may want to also remove Google Chrome from the Terminal using the
sudo apt-get purge ... command (where
... is replaced by the package you want to remove or a space-separated list of the packages you want to remove), or remove it in the Synaptic Package Manager (which you can install in the Software Center if you don't have it; it's itself provided by the package
synaptic) by right-clicking on the packages you want to remove and clicking "Mark for Complete Removal". These ways of removing packages will remove all global (i.e., non-user-specific) configuration files.
(the completely open source counterpart to Chrome), you can do it the same way, just delete
~/.config/chromium. You can also remove the package as mentioned above for Google Chrome.