The RtpDemuxer uses a number of maps, all of which can be made
unordered as they map SSRCs/MIDs/payload types/RSIDs etc - all of which
have no inherent ordering.
In busy media servers, the std::map operations can use ~0.5% CPU. After
this commit has landed, it will be evaluated and if it doesn't live up
to expected savings, it will be reverted.
Bug: webrtc:12689
Change-Id: I99e21c6b1ddb21dd9d47b0f9a891df5a2c3df59a
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/216243
Reviewed-by: Sebastian Jansson <srte@webrtc.org>
Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org>
Commit-Queue: Victor Boivie <boivie@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#33846}
