Add CryptoParams to webrtc::MediaSession.

webrtc/api/ortc/mediadescription.h

 /*
  *  Copyright 2017 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
 #ifndef WEBRTC_API_ORTC_MEDIADESCRIPTION_H_
 #define WEBRTC_API_ORTC_MEDIADESCRIPTION_H_
 
 #include <string>
 #include <utility>
+#include <vector>
 
 #include "webrtc/base/optional.h"
+#include "webrtc/media/base/cryptoparams.h"
 
 namespace webrtc {
 
 // A structured representation of a media description within an SDP session
 // description.
 class MediaDescription {
  public:
   explicit MediaDescription(std::string mid) : mid_(std::move(mid)) {}
 
   ~MediaDescription() {}
 
   // The mid(media stream identification) is used for identifying media streams
   // within a session description.
   // https://tools.ietf.org/html/rfc5888#section-6
   rtc::Optional<std::string> mid() const { return mid_; }
   void set_mid(std::string mid) { mid_.emplace(std::move(mid)); }
 
+  // Security keys and parameters for this media stream. Can be used to
+  // negotiate parameters for SRTP.
+  // https://tools.ietf.org/html/rfc4568#page-5
+  std::vector<cricket::CryptoParams>& sdes_params() { return sdes_params_; }
+  const std::vector<cricket::CryptoParams>& sdes_params() const {
+    return sdes_params_;
+  }
+
  private:
   rtc::Optional<std::string> mid_;
+
+  std::vector<cricket::CryptoParams> sdes_params_;
 };
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_API_ORTC_MEDIADESCRIPTION_H_