I would also like to mention this occurs on my Nexus 5 pretty frequently: I'm at home, using the WiFi, and randomly it just stops working. It just says, for every request I put out, that they time out. The only way to "fix" it is to shut off WiFi, and then turn it back on.
This happened on my Galaxy S3 as well. All other devices in the house (Xbox, laptops with the exception of the MacBook Pro which suffers from this Yosemite issue) have no problems.
There are other issues I've had as well as this in other places with Android, but this is the most annoying one.