For quite a while, Google has encouraged some Google Chrome users to upgrade to a newer and more secure operating system. More specifically, users of Windows XP, Windows Vista and OS X 10.6, 10.7 and 10.8 have been faced with a time limited support for their operating system.
Now, Google state that in April 2016, support for the before mentioned operating systems is coming to an end. At the same time, both Microsoft and Apple end their support of the relatively old operating systems.
The Google Chrome browser will still work on these operating systems, but will no longer receive updates as well as security fixes.