Move optional.h to webrtc/api/

webrtc/modules/pacing/alr_detector.h

 /*
  *  Copyright (c) 2016 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_ALR_DETECTOR_H_
 #define WEBRTC_MODULES_PACING_ALR_DETECTOR_H_
 
+#include "webrtc/api/optional.h"
 #include "webrtc/common_types.h"
 #include "webrtc/modules/pacing/interval_budget.h"
 #include "webrtc/modules/pacing/paced_sender.h"
-#include "webrtc/rtc_base/optional.h"
 #include "webrtc/rtc_base/rate_statistics.h"
 #include "webrtc/typedefs.h"
 
 namespace webrtc {
 
 // Application limited region detector is a class that utilizes signals of
 // elapsed time and bytes sent to estimate whether network traffic is
 // currently limited by the application's ability to generate traffic.
 //
 // AlrDetector provides a signal that can be utilized to adjust
@@ skipping 46 matching lines @@
   int alr_start_budget_level_percent_;
   int alr_stop_budget_level_percent_;
 
   IntervalBudget alr_budget_;
   rtc::Optional<int64_t> alr_started_time_ms_;
 };
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_MODULES_PACING_ALR_DETECTOR_H_