[chromium-discuss] Add chromedriver support for "samesite" cookie attribute

[Kostas Drk]

Hello everyone.

Since the "SameSite" cookie attribute is supported by the browser, it would
make sense for the chromedriver to return it in the cookie object as well.
I have tweaked a few things myself to get it working, but since I am not
super familiar with C++ I didn't submit any code for review. Seems simple
though, so anyone with experience could get it done in a jiffy.

Thanks!
K