Apparently Chrome Beta for OS X is supposed to be 64 bit.
(e.g. http://thenextweb.com/google/2014/08/29/chrome-38-beta-arrives-new-user-switching-profiles-guest-mode-64-bit-default-mac/
I have the latest Chrome beta Version 38.0.2125.77 beta but it is still 32 bit. I have reinstalled.
The dev channel is 64 bit on my Macbook Air (2013).
Best Answer
Downloading this Google Chrome 64-bit version 39.0.2171.2 - you get the correct one.