Fix crash on multiple feedback messages are received on old transport.

Fix crash on multiple feedback messages are received on old transport.

BUG=webrtc:7347
Review-Url: https://codereview.webrtc.org/2753283002
Cr-Commit-Position: refs/heads/master@{#17290}
Committed: https://chromium.googlesource.com/external/webrtc/+/dd20054e06e18663a306df4dd8029d11006b8c05

[stefan-webrtc, 2017-03-17 12:26:54]

stefan@webrtc.org changed reviewers:
+ philipel@webrtc.org

[philipel, 2017-03-17 12:44:27]

lgtm

[stefan-webrtc, 2017-03-17 12:45:29]

The CQ bit was checked by stefan@webrtc.org

[commit-bot: I haz the power, 2017-03-17 12:45:31]

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, 2017-03-17 13:19:11]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1489754729511220, "parent_rev":
"6585f7087cbd087ce6dbc2779199d3b79ab36236", "commit_rev":
"dd20054e06e18663a306df4dd8029d11006b8c05"}

[commit-bot: I haz the power, 2017-03-17 13:19:14]

Description was changed from

==========
Fix crash on multiple feedback messages are received on old transport.

BUG=webrtc:7347
==========

to

==========
Fix crash on multiple feedback messages are received on old transport.

BUG=webrtc:7347

Review-Url: https://codereview.webrtc.org/2753283002
Cr-Commit-Position: refs/heads/master@{#17290}
Committed:
https://chromium.googlesource.com/external/webrtc/+/dd20054e06e18663a306df4dd...
==========

[commit-bot: I haz the power, 2017-03-17 13:19:15]

Committed patchset #1 (id:1) as
https://chromium.googlesource.com/external/webrtc/+/dd20054e06e18663a306df4dd...