Fix notification test to return a promise.

Fix notification test to return a promise.

A recent change to testharness.js (https://codereview.chromium.org/2468053002)
causes promise_test to throw a TypeError exception when the test returns
something other than a promise.

This CL fixes one notification test which was not explicitly returning the
promise.

BUG=662172
Committed: https://crrev.com/eeafa338d2075075df0760d14935c5c9f3102190
Cr-Commit-Position: refs/heads/master@{#429915}

[harkness, 2016-11-04 15:37:49]

harkness@chromium.org changed reviewers:
+ peter@chromium.org

[Peter Beverloo, 2016-11-04 15:42:14]

The CQ bit was checked by peter@chromium.org

[Peter Beverloo, 2016-11-04 15:42:15]

lgtm

[commit-bot: I haz the power, 2016-11-04 15:42:35]

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, 2016-11-04 16:46:26]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-11-04 17:15:59]

Description was changed from

==========
Fix notification test to return a promise.

A recent change to testharness.js (https://codereview.chromium.org/2468053002)
causes promise_test to throw a TypeError exception when the test returns
something other than a promise.

This CL fixes one notification test which was not explicitly returning the
promise.

BUG=662172
==========

to

==========
Fix notification test to return a promise.

A recent change to testharness.js (https://codereview.chromium.org/2468053002)
causes promise_test to throw a TypeError exception when the test returns
something other than a promise.

This CL fixes one notification test which was not explicitly returning the
promise.

BUG=662172

Committed: https://crrev.com/eeafa338d2075075df0760d14935c5c9f3102190
Cr-Commit-Position: refs/heads/master@{#429915}
==========

[commit-bot: I haz the power, 2016-11-04 17:15:59]

Patchset 1 (id:??) landed as
https://crrev.com/eeafa338d2075075df0760d14935c5c9f3102190
Cr-Commit-Position: refs/heads/master@{#429915}