Handle case of empty connection in pair change event
Handle case of empty connection in pair change event

Bug: webrtc:10878
Change-Id: I49992bac3450e95b0f8aa388e21662f2d6f92a96
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/149029
Reviewed-by: Qingsi Wang <1c4f50fe02fab79f81be17f4e2f574c199f33efd@webrtc.org>
Commit-Queue: Alex Drake <4b3778eb49ac1c76affa4d7a2aa3419feb8ae009@google.com>
Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#28850}

TimothyGu/libilbc,TimothyGu/libilbc,TimothyGu/libilbc,ShiftMediaProject/libilbc,ShiftMediaProject/libilbc,ShiftMediaProject/libilbc,ShiftMediaProject/libilbc,ShiftMediaProject/libilbc,TimothyGu/libilbc,TimothyGu/libilbc