OPUS_GET_IN_DTX was added 2019-04-15, but we still need to support
building on systems with older versions of the Opus headers (eg. Debian
Jessie, released 2015-04-25). This is needed to fix the "Build From
Tarball" bot [1].
[1] https://ci.chromium.org/p/infra/builders/cron/Build%20From%20Tarball
BUG=chromium:1047860,webrtc:11085
R=minyue@webrtc.org,henrick.lundin@webrtc.org
Change-Id: I5418c3caf4d2c7da9b9ba43ce85879b1e0eec6e6
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/168560
Reviewed-by: Minyue Li <minyue@webrtc.org>
Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
Reviewed-by: Tommi <tommi@webrtc.org>
Commit-Queue: Thomas Anderson <thomasanderson@chromium.org>
Cr-Commit-Position: refs/heads/master@{#30612}
422f9dd5df