The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/cb392e65b5b628539cb970a1268c39c40f425ee1

commit cb392e65b5b628539cb970a1268c39c40f425ee1
Author: battre <battre@chromium.org>
Date: Thu Mar 31 14:32:35 2016

Allow to reset credential manager first run experience

Allow a tester to reset the first run experience state of the credential
manager API by loading the URL chrome://password-manager-internals/?reset_fre in a
tab.

BUG= 599441 

Review URL: https://codereview.chromium.org/1846943002

Cr-Commit-Position: refs/heads/master@{#384273}

[modify] https://crrev.com/cb392e65b5b628539cb970a1268c39c40f425ee1/chrome/browser/ui/webui/password_manager_internals/password_manager_internals_ui.cc
[modify] https://crrev.com/cb392e65b5b628539cb970a1268c39c40f425ee1/chrome/browser/ui/webui/password_manager_internals/password_manager_internals_ui.h

Once this lands on dev-channel, you can open 
  chrome://password-manager-internals/?reset_fre
and should see a message "Reset auto sign-in first run experience: yes" to confirm the success.