Move optional.h to webrtc/api/

webrtc/modules/pacing/paced_sender.h

 /*
  *  Copyright (c) 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.
  */
 
 #ifndef WEBRTC_MODULES_PACING_PACED_SENDER_H_
 #define WEBRTC_MODULES_PACING_PACED_SENDER_H_
 
 #include <list>
 #include <memory>
 #include <set>
 
+#include "webrtc/api/optional.h"
 #include "webrtc/modules/pacing/pacer.h"
 #include "webrtc/rtc_base/criticalsection.h"
-#include "webrtc/rtc_base/optional.h"
 #include "webrtc/rtc_base/thread_annotations.h"
 #include "webrtc/typedefs.h"
 
 namespace webrtc {
 class AlrDetector;
 class BitrateProber;
 class Clock;
 class ProbeClusterCreatedObserver;
 class RtcEventLog;
 class IntervalBudget;
@@ skipping 162 matching lines @@
 
   std::unique_ptr<paced_sender::PacketQueue> packets_ GUARDED_BY(critsect_);
   uint64_t packet_counter_;
   ProcessThread* process_thread_ = nullptr;
 
   float pacing_factor_ GUARDED_BY(critsect_);
   int64_t queue_time_limit GUARDED_BY(critsect_);
 };
 }  // namespace webrtc
 #endif  // WEBRTC_MODULES_PACING_PACED_SENDER_H_