I'm using a Macintosh running Mavericks (10.9.5), Chrome 38.0.2125.122, and according to adobe.com, I have Flash version 15,0,0,223 in Chrome and should have version 220.127.116.11. It sounds like my system is quite a bit behind on Flash versions. I just got back from a cruise where I had very limited internet connectivity -- don't know if that contributed to the problem. I don't remember ever installing any special version of Flash, and don't see any Flash related extensions.
I tried trashing the google chrome.app from the Macintosh, emptied the trash, and reinstalled google chrome from a download. I see exactly the same thing - same bookmarks, same extensions and -- most importantly, adobe.com still says Flash reader is at version 18.104.22.168; any idea of what's going on?
The answer turned out to be ... wait.
Eventually, hours later, I got an update to the next version of Chrome (39.x) and with that update Adobe Flash updated to the current version.