Move optional.h to webrtc/api/

webrtc/api/mediastreaminterface.h

 /*
  *  Copyright 2012 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.
  */
 
 // This file contains interfaces for MediaStream, MediaTrack and MediaSource.
 // These interfaces are used for implementing MediaStream and MediaTrack as
 // defined in http://dev.w3.org/2011/webrtc/editor/webrtc.html#stream-api. These
 // interfaces must be used only with PeerConnection. PeerConnectionManager
 // interface provides the factory methods to create MediaStream and MediaTracks.
 
 #ifndef WEBRTC_API_MEDIASTREAMINTERFACE_H_
 #define WEBRTC_API_MEDIASTREAMINTERFACE_H_
 
 #include <stddef.h>
 
 #include <string>
 #include <vector>
 
+#include "webrtc/api/optional.h"
 #include "webrtc/api/video/video_frame.h"
-#include "webrtc/rtc_base/optional.h"
 // TODO(zhihuang): Remove unrelated headers once downstream applications stop
 // relying on them; they were previously transitively included by
 // mediachannel.h, which is no longer a dependency of this file.
 #include "webrtc/media/base/streamparams.h"
 #include "webrtc/media/base/videosinkinterface.h"
 #include "webrtc/media/base/videosourceinterface.h"
 #include "webrtc/rtc_base/ratetracker.h"
 #include "webrtc/rtc_base/refcount.h"
 #include "webrtc/rtc_base/scoped_ref_ptr.h"
 #include "webrtc/rtc_base/thread.h"
@@ skipping 277 matching lines @@
   virtual bool RemoveTrack(AudioTrackInterface* track) = 0;
   virtual bool RemoveTrack(VideoTrackInterface* track) = 0;
 
  protected:
   virtual ~MediaStreamInterface() {}
 };
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_API_MEDIASTREAMINTERFACE_H_