Fix ThreadTaskRunnerHandle check in BrowserContext.

Fix ThreadTaskRunnerHandle check in BrowserContext.

We want IsSet(), not Get(). Get() DCHECKs if null.

BUG=
TBR=ben@chromium.org

Committed: https://crrev.com/dced2d04ce3484e6830e1f971dfbf571b5e2771c
Cr-Commit-Position: refs/heads/master@{#403262}

[Ken Rockot(use gerrit already), 2016-06-30 17:52:23]

Description was changed from

==========
Fix ThreadTaskRunnerHandle check in BrowserContext.

We want IsSet(), not Get(). Get() DCHECKs if null.

BUG=
R=ben@chromium.org
==========

to

==========
Fix ThreadTaskRunnerHandle check in BrowserContext.

We want IsSet(), not Get(). Get() DCHECKs if null.

BUG=
TBR=ben@chromium.org
==========

[Ken Rockot(use gerrit already), 2016-06-30 17:52:30]

The CQ bit was checked by rockot@chromium.org

[commit-bot: I haz the power, 2016-06-30 17:52:55]

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, 2016-06-30 17:55:08]

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

[commit-bot: I haz the power, 2016-06-30 17:55:09]

Try jobs failed on following builders:
  ios-device-gn on master.tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/ios-device-gn/bui...)

[Ken Rockot(use gerrit already), 2016-06-30 19:05:21]

The CQ bit was checked by rockot@chromium.org

[commit-bot: I haz the power, 2016-06-30 19:06:39]

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, 2016-06-30 20:08:39]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-06-30 20:09:00]

CQ bit was unchecked.

[commit-bot: I haz the power, 2016-06-30 20:11:44]

Description was changed from

==========
Fix ThreadTaskRunnerHandle check in BrowserContext.

We want IsSet(), not Get(). Get() DCHECKs if null.

BUG=
TBR=ben@chromium.org
==========

to

==========
Fix ThreadTaskRunnerHandle check in BrowserContext.

We want IsSet(), not Get(). Get() DCHECKs if null.

BUG=
TBR=ben@chromium.org

Committed: https://crrev.com/dced2d04ce3484e6830e1f971dfbf571b5e2771c
Cr-Commit-Position: refs/heads/master@{#403262}
==========

[commit-bot: I haz the power, 2016-06-30 20:11:49]

Patchset 1 (id:??) landed as
https://crrev.com/dced2d04ce3484e6830e1f971dfbf571b5e2771c
Cr-Commit-Position: refs/heads/master@{#403262}