Fix the Chrome crash caused by RtcEventLog

Fix the Chrome crash caused by RtcEventLog

Stop the RtcEventLog when the PeerConnection is closed so that Chrome
will not crash because of creating too many threads.

BUG=chromium:687553
Review-Url: https://codereview.webrtc.org/2682433005
Cr-Commit-Position: refs/heads/master@{#16482}
Committed: https://chromium.googlesource.com/external/webrtc/+/7798501d7a20129d45889aac6854f00a55f20445

[Zhi Huang, 2017-02-07 02:35:06]

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

[commit-bot: I haz the power, 2017-02-07 02:35:11]

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, 2017-02-07 03:22:32]

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

[commit-bot: I haz the power, 2017-02-07 03:22:33]

Dry run: This issue passed the CQ dry run.

[Taylor Brandstetter, 2017-02-07 21:14:16]

deadbeef@webrtc.org changed reviewers:
+ deadbeef@webrtc.org

[Taylor Brandstetter, 2017-02-07 21:14:17]

lgtm

[Taylor Brandstetter, 2017-02-07 21:15:37]

https://codereview.webrtc.org/2682433005/diff/1/webrtc/pc/peerconnection.cc
File webrtc/pc/peerconnection.cc (right):

https://codereview.webrtc.org/2682433005/diff/1/webrtc/pc/peerconnection.cc#n...
webrtc/pc/peerconnection.cc:2578: event_log_->StopLogging();
Actually, we should check if event_log_ is null or not here. And maybe add a
test for this in peerconnectioninterface_unittest.cc.

[Zhi Huang, 2017-02-07 21:58:19]

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

[commit-bot: I haz the power, 2017-02-07 21:58:32]

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, 2017-02-07 22:30:51]

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

[commit-bot: I haz the power, 2017-02-07 22:30:52]

Dry run: Try jobs failed on following builders:
  linux_memcheck on master.tryserver.webrtc (JOB_FAILED,
http://build.chromium.org/p/tryserver.webrtc/builders/linux_memcheck/builds/4924)

[Zhi Huang, 2017-02-07 23:12:26]

The CQ bit was checked by zhihuang@webrtc.org

[Zhi Huang, 2017-02-07 23:12:27]

The patchset sent to the CQ was uploaded after l-g-t-m from deadbeef@webrtc.org
Link to the patchset: https://codereview.webrtc.org/2682433005/#ps20001 (title:
"Add a unit test.")

[commit-bot: I haz the power, 2017-02-07 23:12:34]

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

[Taylor Brandstetter, 2017-02-07 23:15:11]

lgtm for the updated patchset

[commit-bot: I haz the power, 2017-02-07 23:45:17]

CQ is committing da patch.

Bot data: {"patchset_id": 20001, "attempt_start_ts": 1486509146975790,
"parent_rev": "9dd77baca440ed3053eeca5f84ec2e4810401d9f", "commit_rev":
"7798501d7a20129d45889aac6854f00a55f20445"}

[commit-bot: I haz the power, 2017-02-07 23:45:20]

Description was changed from

==========
Fix the Chrome crash caused by RtcEventLog

Stop the RtcEventLog when the PeerConnection is closed so that Chrome
will not crash because of creating too many threads.

BUG=chromium:687553
==========

to

==========
Fix the Chrome crash caused by RtcEventLog

Stop the RtcEventLog when the PeerConnection is closed so that Chrome
will not crash because of creating too many threads.

BUG=chromium:687553

Review-Url: https://codereview.webrtc.org/2682433005
Cr-Commit-Position: refs/heads/master@{#16482}
Committed:
https://chromium.googlesource.com/external/webrtc/+/7798501d7a20129d45889aac6...
==========

[commit-bot: I haz the power, 2017-02-07 23:45:22]

Committed patchset #2 (id:20001) as
https://chromium.googlesource.com/external/webrtc/+/7798501d7a20129d45889aac6...