Google password "required" auto message from OS X
I've been an Apple user for years and for the first time I am getting an auto message on my computer screen from OS X asking me to enter my Google password.
Why is this? Is this a computer hacker or is this Apple for real? I need to see this in writing. I am not entering my password so that someone can access my computer.
I would appreciate a response!
Thanks!
MacBook Air (13-inch Mid 2013), OS X Yosemite (10.10.3)