Fix DCHECK in the chromoting host when disconnecting a WebRTC connection.

Fix DCHECK in the chromoting host when disconnecting a WebRTC connection.

WebRTC creates threads internally. Thread::Stop() is a blocking operation,
so it's not allowed on the network thread. To work around this problem
WebrtcTransport::PeerConnectionWrapper uses ScopedAllowIO when closing
PeerConnection. But it's not longer enough - some threads are stopped
later when the factory is destroyed. Updated PeerConnectionWrapper
destructor to destroy the PeerConnectionFactory with ScopedAllowIO.

BUG=714699
Review-Url: https://codereview.chromium.org/2847803003
Cr-Commit-Position: refs/heads/master@{#467838}
Committed: https://chromium.googlesource.com/chromium/src/+/8c6a6fa53691f5a3f55023cc003e9c665083ea34

[Sergey Ulanov, 2017-04-27 19:20:01]

sergeyu@chromium.org changed reviewers:
+ jamiewalch@chromium.org

[Jamie, 2017-04-27 20:37:58]

LGTM, thanks!

[Sergey Ulanov, 2017-04-27 20:46:34]

The CQ bit was checked by sergeyu@chromium.org

[commit-bot: I haz the power, 2017-04-27 20:47:17]

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, 2017-04-27 21:11:08]

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

[commit-bot: I haz the power, 2017-04-27 21:11:08]

Try jobs failed on following builders:
  chromeos_amd64-generic_chromium_compile_only_ng on
master.tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/chromeos_amd64-...)
  chromeos_daisy_chromium_compile_only_ng on master.tryserver.chromium.linux
(JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/chromeos_daisy_...)

[Sergey Ulanov, 2017-04-27 21:51:41]

The CQ bit was checked by sergeyu@chromium.org

[commit-bot: I haz the power, 2017-04-27 21:52:04]

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, 2017-04-28 02:11:12]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1493329901941060, "parent_rev":
"3e1e45d504e7f8d83b2fa9bf61de997ad79ec05f", "commit_rev":
"8c6a6fa53691f5a3f55023cc003e9c665083ea34"}

[commit-bot: I haz the power, 2017-04-28 02:11:19]

Description was changed from

==========
Fix DCHECK in the chromoting host when disconnecting a WebRTC connection.

WebRTC creates threads internally. Thread::Stop() is a blocking operation,
so it's not allowed on the network thread. To work around this problem
WebrtcTransport::PeerConnectionWrapper uses ScopedAllowIO when closing
PeerConnection. But it's not longer enough - some threads are stopped
later when the factory is destroyed. Updated PeerConnectionWrapper
destructor to destroy the PeerConnectionFactory with ScopedAllowIO.

BUG=714699
==========

to

==========
Fix DCHECK in the chromoting host when disconnecting a WebRTC connection.

WebRTC creates threads internally. Thread::Stop() is a blocking operation,
so it's not allowed on the network thread. To work around this problem
WebrtcTransport::PeerConnectionWrapper uses ScopedAllowIO when closing
PeerConnection. But it's not longer enough - some threads are stopped
later when the factory is destroyed. Updated PeerConnectionWrapper
destructor to destroy the PeerConnectionFactory with ScopedAllowIO.

BUG=714699

Review-Url: https://codereview.chromium.org/2847803003
Cr-Commit-Position: refs/heads/master@{#467838}
Committed:
https://chromium.googlesource.com/chromium/src/+/8c6a6fa53691f5a3f55023cc003e...
==========

[commit-bot: I haz the power, 2017-04-28 02:11:30]

Committed patchset #1 (id:1) as
https://chromium.googlesource.com/chromium/src/+/8c6a6fa53691f5a3f55023cc003e...