A field has been added to "CryptoOptions" to enable SRTP_AES128_CM_SHA1_32 from native apps if really necessary. R=deadbeef@webrtc.org Bug: webrtc:7670 Change-Id: I36b6ab3e302fbf3cda2611ff196757e43a56e704 Reviewed-on: https://webrtc-review.googlesource.com/41420 Reviewed-by: Taylor Brandstetter <deadbeef@webrtc.org> Reviewed-by: Magnus Jedvert <magjed@webrtc.org> Commit-Queue: Joachim Bauch <jbauch@webrtc.org> Cr-Commit-Position: refs/heads/master@{#21952}