commit b140b9fd695c30f22016d2b6360caf6d1f525dff
author Taylor Brandstetter <deadbeef@webrtc.org> Fri Oct 13 00:24:16 2017
committer Commit Bot <commit-bot@chromium.org> Fri Oct 13 05:11:27 2017
tree 152714c32be031d8b328f9780e49d82d017c4743
parent f0229767d1835d5857041298ede6348aa8423980

Keep count of libsrtp clients, and only deinitialize when it goes to 0.

This is the same thing we're doing for usrsctp. Before this CL, the
first SrtpSession to call SetKey would initialize libsrtp, and
ChannelManager's destructor would deinitialize it. This works for an
application that only uses one instance of ChannelManager simultaneously
(or one instance of PeerConnectionFactory), but not one that uses
multiple.

Now, libsrtp is effectively reference-counted, with the first
SrtpSession to take a reference initializing it, and the last to remove
its reference deinitializing it.

This issue was discovered recently due to a change that resulted in
using srtp_update. Without using that method, the issue went unnoticed;
maybe srtp_protect/srtp_unprotect don't require initialization?

Bug: webrtc:8388
Change-Id: If1329360f0b469e454810e62e9b5acfbd4cba100
Reviewed-on: https://webrtc-review.googlesource.com/9000
Commit-Queue: Taylor Brandstetter <deadbeef@webrtc.org>
Reviewed-by: Steve Anton <steveanton@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#20262}