5de068082b
Ensure that the ring buffer does not return a pointer into the buffer if no data is available to read. The ring buffer fix is not directly applicable to issue webrtc:7845, but may cause related memory errors. BUG=webrtc:7845 Review-Url: https://codereview.webrtc.org/2971313002 Cr-Commit-Position: refs/heads/master@{#18940}