Move optional.h to webrtc/api/

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/api/optional.h"
 #include "webrtc/media/base/cryptoparams.h"
-#include "webrtc/rtc_base/optional.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() {}
@@ skipping 14 matching lines @@
 
  private:
   rtc::Optional<std::string> mid_;
 
   std::vector<cricket::CryptoParams> sdes_params_;
 };
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_API_ORTC_MEDIADESCRIPTION_H_