Remove calls to deprecated MessageLoop methods in components/previews/.

Remove calls to deprecated MessageLoop methods in components/previews/.

This CL removes calls to MessageLoop::RunUntilIdle from
components/previews/.

BUG=616447
Committed: https://crrev.com/fb7015f91f55995956e2c07d52cef3b95eb60801
Cr-Commit-Position: refs/heads/master@{#418921}

[fdoray, 2016-09-15 17:04:12]

fdoray@chromium.org changed reviewers:
+ kundaji@chromium.org

[fdoray, 2016-09-15 17:04:13]

PTAL

[Not at Google. Contact bengr, 2016-09-15 17:38:23]

lgtm

[fdoray, 2016-09-15 18:04:27]

The CQ bit was checked by fdoray@chromium.org

[commit-bot: I haz the power, 2016-09-15 18:05:09]

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, 2016-09-15 18:52:08]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-09-15 18:53:52]

Description was changed from

==========
Remove calls to deprecated MessageLoop methods in components/previews/.

This CL removes calls to MessageLoop::RunUntilIdle from
components/previews/.

BUG=616447
==========

to

==========
Remove calls to deprecated MessageLoop methods in components/previews/.

This CL removes calls to MessageLoop::RunUntilIdle from
components/previews/.

BUG=616447

Committed: https://crrev.com/fb7015f91f55995956e2c07d52cef3b95eb60801
Cr-Commit-Position: refs/heads/master@{#418921}
==========

[commit-bot: I haz the power, 2016-09-15 18:53:53]

Patchset 1 (id:??) landed as
https://crrev.com/fb7015f91f55995956e2c07d52cef3b95eb60801
Cr-Commit-Position: refs/heads/master@{#418921}