Update: Announced in version 50 of Chrome OS, Material Design is now enabled by default on Mac with this latest update. Those who have pointed out how “un-Maclike” it looks can switch back to the older Non-Material design by going to Chrome flags here.
Chrome 52 is rolling out now to Mac, Windows, and Linux. The latest version of the Google browser contains the usual bug and security fixes, but notably removes the ability to use “backspace” as a return shortcut. It also adds several developer features to improve browser performance.