Add QWAVE/DSCP support for unconnected sockets.  Create a helper class for maintaining remote addresses that have been configured for dscp.  Adapted from cl 682456.

Bug: webrtc:5836
Change-Id: I2ded915e82a7e967962ff3b1f4027b422d055157
Reviewed-on: https://chromium-review.googlesource.com/1191925
Commit-Queue: Tim Haloun <thaloun@chromium.org>
Reviewed-by: Ryan Hamilton <rch@chromium.org>
Cr-Commit-Position: refs/heads/master@{#594931}
3 files changed