PacketBuffer now can save how many times a packet has been nacked.
Also save size/max nack count in the FrameObject/RtpFrameObject.

BUG=webrtc:5514
R=stefan@webrtc.org

Review URL: https://codereview.webrtc.org/1988653002 .

Cr-Original-Commit-Position: refs/heads/master@{#12863}
Cr-Mirrored-From: https://chromium.googlesource.com/external/webrtc
Cr-Mirrored-Commit: 5ceaaae3689cac9ae10dc7caf5802e8d6e0c7a99
6 files changed