Version: Version 51.0.2703.0 canary (64-bit)
OS: Mac OS X 10.11.4

What steps will reproduce the problem?
(1) go to https://legacy-cma-dot-credential-management-sample.appspot.com/signin
(2) sign in using "agektmr@gmail.com" for email and "test" for password
(3) password saving dialog shows up twice
(4) sign out
(5) press "sing in" shows 2 identical accounts in account chooser

What is the expected output?
- password saving dialog to show up only once
- single account shows up on account chooser

Note that
- chrome://settings/passwords show single account
- accounts bubble shows single account (click key icon in omni bar)