Add test for ReadingListMediator

Add test for ReadingListMediator

Test ReadingListMediator for filling read and unread array.

BUG=721758
Review-Url: https://codereview.chromium.org/2917363004
Cr-Commit-Position: refs/heads/master@{#477341}
Committed: https://chromium.googlesource.com/chromium/src/+/0ff947cea6682a0cc4b8e7578b4d43534140e843

[gambard, 2017-06-06 15:22:18]

gambard@chromium.org changed reviewers:
+ jif@chromium.org

[gambard, 2017-06-06 15:22:18]

PTAL, I forgot the test in the previous CL :(

[jif, 2017-06-06 16:39:53]

The CQ bit was checked by jif@chromium.org

[jif, 2017-06-06 16:39:53]

lgtm

[commit-bot: I haz the power, 2017-06-06 16:40:20]

CQ is trying da patch.

Follow status at:
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-06-06 18:07:14]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1496767193663370, "parent_rev":
"ba9f2bb42a6f241076156541a84e8767e08cf66c", "commit_rev":
"0ff947cea6682a0cc4b8e7578b4d43534140e843"}

[commit-bot: I haz the power, 2017-06-06 18:07:23]

Description was changed from

==========
Add test for ReadingListMediator

Test ReadingListMediator for filling read and unread array.

BUG=721758
==========

to

==========
Add test for ReadingListMediator

Test ReadingListMediator for filling read and unread array.

BUG=721758

Review-Url: https://codereview.chromium.org/2917363004
Cr-Commit-Position: refs/heads/master@{#477341}
Committed:
https://chromium.googlesource.com/chromium/src/+/0ff947cea6682a0cc4b8e7578b4d...
==========

[commit-bot: I haz the power, 2017-06-06 18:07:24]

Committed patchset #1 (id:1) as
https://chromium.googlesource.com/chromium/src/+/0ff947cea6682a0cc4b8e7578b4d...