Make rtp::Packet's destructor and constructors public

This will allow the RTP-related subclasses of RtcEvent keep an rtp::Packet for the header, rather than hold the heaver, and at the moment unnecessary for logging, RtpPacketReceived/RtpPacketToSend.

BUG=webrtc:8111

Review-Url: https://codereview.webrtc.org/3013023004
Cr-Original-Commit-Position: refs/heads/master@{#19812}
Cr-Mirrored-From: https://chromium.googlesource.com/external/webrtc
Cr-Mirrored-Commit: 87443ee3e69abf8dbf656952d29501daa248ff2c
1 file changed