Presentation API: clean up around usage of promises.

Presentation API: clean up around usage of promises.

I wrote this while investigating a Promise issue. I think it wouldn't
hurt to land it :)

BUG=None

Committed: https://crrev.com/02e29a49876c306d27776ca186663cd147328e7b
Cr-Commit-Position: refs/heads/master@{#407184}

[mlamouri (slow - plz ping), 2016-07-22 14:39:40]

mlamouri@chromium.org changed reviewers:
+ avayvod@chromium.org

[mlamouri (slow - plz ping), 2016-07-22 14:39:41]

avayvod@, PTAL

[mlamouri (slow - plz ping), 2016-07-22 14:39:52]

The CQ bit was checked by mlamouri@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2016-07-22 14:40:03]

Dry run: 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, 2016-07-22 15:56:17]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2016-07-22 15:56:18]

Dry run: This issue passed the CQ dry run.

[whywhat, 2016-07-22 17:07:45]

lgtm

[mlamouri (slow - plz ping), 2016-07-22 17:09:20]

The CQ bit was checked by mlamouri@chromium.org

[commit-bot: I haz the power, 2016-07-22 17:09:52]

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, 2016-07-22 17:13:36]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-07-22 17:16:47]

Description was changed from

==========
Presentation API: clean up around usage of promises.

I wrote this while investigating a Promise issue. I think it wouldn't
hurt to land it :)

BUG=None
==========

to

==========
Presentation API: clean up around usage of promises.

I wrote this while investigating a Promise issue. I think it wouldn't
hurt to land it :)

BUG=None

Committed: https://crrev.com/02e29a49876c306d27776ca186663cd147328e7b
Cr-Commit-Position: refs/heads/master@{#407184}
==========

[commit-bot: I haz the power, 2016-07-22 17:16:48]

Patchset 1 (id:??) landed as
https://crrev.com/02e29a49876c306d27776ca186663cd147328e7b
Cr-Commit-Position: refs/heads/master@{#407184}