The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/1cecb82cc1f43f51f1daf68c846c02506965fc69

commit 1cecb82cc1f43f51f1daf68c846c02506965fc69
Author: mamir <mamir@chromium.org>
Date: Thu Jun 08 17:21:00 2017

[NTP::Push] Adding Breaking News Subscription Manager

It wraps around the functionality in SubscriptionJsonRequest (and later UnsubscriptionJsonRequest)

BUG= 728697 

Review-Url: https://codereview.chromium.org/2914263002
Cr-Commit-Position: refs/heads/master@{#478006}

[modify] https://crrev.com/1cecb82cc1f43f51f1daf68c846c02506965fc69/chrome/browser/prefs/browser_prefs.cc
[modify] https://crrev.com/1cecb82cc1f43f51f1daf68c846c02506965fc69/components/ntp_snippets/BUILD.gn
[add] https://crrev.com/1cecb82cc1f43f51f1daf68c846c02506965fc69/components/ntp_snippets/breaking_news/subscription_manager.cc
[add] https://crrev.com/1cecb82cc1f43f51f1daf68c846c02506965fc69/components/ntp_snippets/breaking_news/subscription_manager.h
[add] https://crrev.com/1cecb82cc1f43f51f1daf68c846c02506965fc69/components/ntp_snippets/breaking_news/subscription_manager_unittest.cc
[modify] https://crrev.com/1cecb82cc1f43f51f1daf68c846c02506965fc69/components/ntp_snippets/pref_names.cc
[modify] https://crrev.com/1cecb82cc1f43f51f1daf68c846c02506965fc69/components/ntp_snippets/pref_names.h