Add visualization of late feedback packets, and avoid plotting incorrect delays computed based on those.
Add visualization of late feedback packets, and avoid plotting incorrect delays computed based on those.

BUG=None

Review-Url: https://codereview.webrtc.org/3009823002
Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#19705}

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