The check triggered in 30 / 1000 cases of running PeerConnectionIntegrationTest.CallTransferredForCaller locally, far more often than expected.
It will soon be replaced by more graceful handling.
BUG=webrtc:7845
Review-Url: https://codereview.webrtc.org/2975043002
Cr-Commit-Position: refs/heads/master@{#18983}