Add a missing DCHECK to PlatformThread::SetPriority.

Add a missing DCHECK to PlatformThread::SetPriority.
This DCHECK is for the 'new and improved' way of setting thread priority.
What could happen is that code that's migrating over to the new method
might still have a lingering SetPriority call, that could incorrectly bind the
'spawned_thread_checker_' to the construction thread.

BUG=none

Review-Url: https://codereview.webrtc.org/2753423002
Cr-Commit-Position: refs/heads/master@{#17305}
Committed: https://chromium.googlesource.com/external/webrtc/+/7c3da271419ceeef6601c99dcb5cb5400b7157c4

[tommi, 2017-03-18 23:54:04]

tommi@webrtc.org changed reviewers:
+ kthelgason@webrtc.org

[tommi, 2017-03-18 23:54:09]

The CQ bit was checked by tommi@webrtc.org to run a CQ dry run

[commit-bot: I haz the power, 2017-03-18 23:54:13]

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

[commit-bot: I haz the power, 2017-03-19 00:12:46]

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

[commit-bot: I haz the power, 2017-03-19 00:12:47]

Dry run: This issue passed the CQ dry run.

[kthelgason, 2017-03-20 08:27:33]

lgtm

[tommi, 2017-03-20 10:25:19]

The CQ bit was checked by tommi@webrtc.org

[commit-bot: I haz the power, 2017-03-20 10:25:29]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.webrtc.org/...

[commit-bot: I haz the power, 2017-03-20 10:47:18]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1490005519226120, "parent_rev":
"5bf9def61b916477898dd1d33f0f34b2c8df7056", "commit_rev":
"7c3da271419ceeef6601c99dcb5cb5400b7157c4"}

[commit-bot: I haz the power, 2017-03-20 10:47:20]

Description was changed from

==========
Add a missing DCHECK to PlatformThread::SetPriority.
This DCHECK is for the 'new and improved' way of setting thread priority.
What could happen is that code that's migrating over to the new method
might still have a lingering SetPriority call, that could incorrectly bind the
'spawned_thread_checker_' to the construction thread.

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

to

==========
Add a missing DCHECK to PlatformThread::SetPriority.
This DCHECK is for the 'new and improved' way of setting thread priority.
What could happen is that code that's migrating over to the new method
might still have a lingering SetPriority call, that could incorrectly bind the
'spawned_thread_checker_' to the construction thread.

BUG=none

Review-Url: https://codereview.webrtc.org/2753423002
Cr-Commit-Position: refs/heads/master@{#17305}
Committed:
https://chromium.googlesource.com/external/webrtc/+/7c3da271419ceeef6601c99dc...
==========

[commit-bot: I haz the power, 2017-03-20 10:47:21]

Committed patchset #1 (id:1) as
https://chromium.googlesource.com/external/webrtc/+/7c3da271419ceeef6601c99dc...