Somewhat related: I recently added an AccessTokenFetcher helper class (components/signin/core/browser/access_token_fetcher.h) that we should use in the fetcher, instead of manually doing the OAuth dance. Would probably be good to have test coverage before changing the implementation :)

The CL that should land soon does not cover the "authentication in progress" case as it requires more changes (instead FakeSigninManagerBase use FakeSigninManager which does not exist on ChromeOS).

(presumably: the AuthInProgress state doesn't actually exist on Android, so adding this unit-test is low-priority)

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/70957b2671edd5d21ec7b8a6cd36c0cc1f92df99

commit 70957b2671edd5d21ec7b8a6cd36c0cc1f92df99
Author: jkrcal <jkrcal@chromium.org>
Date: Tue Feb 07 10:13:07 2017

[Remote fetcher] Add unit-tests for the authenticated case

This CL adds basic tests for authenticated fetches of
remote_suggestions_fetcher.

BUG= 688310 

Review-Url: https://codereview.chromium.org/2672253003
Cr-Commit-Position: refs/heads/master@{#448581}

[modify] https://crrev.com/70957b2671edd5d21ec7b8a6cd36c0cc1f92df99/components/ntp_snippets/remote/remote_suggestions_fetcher_unittest.cc