1. Packet reception statistics (PLR and RPLR) calculated on each stream separately.
2. Algorithm changed from considering separate quadrants of the sequence-number-ring to simply looking at the oldest in-window SENT packet.
BUG=webrtc:7058
Review-Url: https://codereview.webrtc.org/2632203002
Cr-Commit-Position: refs/heads/master@{#17018}