services/ui: Add WindowServerTestHelper.

services/ui: Add WindowServerTestHelper.

Refactor the code to initialize WindowServer, MessageLoop etc. in tests
into WindowServerTestHelper so that it can be reused.

BUG=none

Committed: https://crrev.com/9d270b260c2363679f130741f8f0e5122c0bdd3b
Cr-Commit-Position: refs/heads/master@{#418015}

[sadrul, 2016-09-10 00:58:27]

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

[commit-bot: I haz the power, 2016-09-10 00:58:50]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[sadrul, 2016-09-10 01:01:51]

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

[sadrul, 2016-09-10 01:02:04]

sadrul@chromium.org changed reviewers:
+ sky@chromium.org

[commit-bot: I haz the power, 2016-09-10 01:02:06]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[sadrul, 2016-09-10 01:06:30]

The notable change in here is probably that ~WindowServerTestHelper explicitly
destroys the WindowServer while the message-loop is still alive. (this came up
from the test failures in https://codereview.chromium.org/2329543002)

[commit-bot: I haz the power, 2016-09-10 01:48:38]

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

[commit-bot: I haz the power, 2016-09-10 01:48:39]

Dry run: This issue passed the CQ dry run.

[sky, 2016-09-12 16:44:49]

LGTM

[sadrul, 2016-09-12 19:18:15]

The CQ bit was checked by sadrul@chromium.org

[commit-bot: I haz the power, 2016-09-12 19:18:51]

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, 2016-09-12 20:05:44]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2016-09-12 20:07:52]

Description was changed from

==========
services/ui: Add WindowServerTestHelper.

Refactor the code to initialize WindowServer, MessageLoop etc. in tests
into WindowServerTestHelper so that it can be reused.

BUG=none
==========

to

==========
services/ui: Add WindowServerTestHelper.

Refactor the code to initialize WindowServer, MessageLoop etc. in tests
into WindowServerTestHelper so that it can be reused.

BUG=none

Committed: https://crrev.com/9d270b260c2363679f130741f8f0e5122c0bdd3b
Cr-Commit-Position: refs/heads/master@{#418015}
==========

[commit-bot: I haz the power, 2016-09-12 20:07:53]

Patchset 2 (id:??) landed as
https://crrev.com/9d270b260c2363679f130741f8f0e5122c0bdd3b
Cr-Commit-Position: refs/heads/master@{#418015}