Move optional.h to webrtc/api/

webrtc/video/receive_statistics_proxy.h

 /*
  *  Copyright (c) 2013 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_VIDEO_RECEIVE_STATISTICS_PROXY_H_
 #define WEBRTC_VIDEO_RECEIVE_STATISTICS_PROXY_H_
 
 #include <map>
 #include <string>
 
+#include "webrtc/api/optional.h"
 #include "webrtc/call/video_receive_stream.h"
 #include "webrtc/common_types.h"
 #include "webrtc/common_video/include/frame_callback.h"
 #include "webrtc/modules/video_coding/include/video_coding_defines.h"
 #include "webrtc/rtc_base/criticalsection.h"
 #include "webrtc/rtc_base/moving_max_counter.h"
-#include "webrtc/rtc_base/optional.h"
 #include "webrtc/rtc_base/rate_statistics.h"
 #include "webrtc/rtc_base/ratetracker.h"
 #include "webrtc/rtc_base/thread_annotations.h"
 #include "webrtc/video/quality_threshold.h"
 #include "webrtc/video/report_block_stats.h"
 #include "webrtc/video/stats_counter.h"
 #include "webrtc/video/video_stream_decoder.h"
 
 namespace webrtc {
 
@@ skipping 144 matching lines @@
   VideoContentType last_content_type_ GUARDED_BY(&crit_);
   rtc::Optional<int64_t> last_decoded_frame_time_ms_ GUARDED_BY(&crit_);
   // Mutable because calling Max() on MovingMaxCounter is not const. Yet it is
   // called from const GetStats().
   mutable rtc::MovingMaxCounter<TimingFrameInfo> timing_frame_info_counter_
       GUARDED_BY(&crit_);
 };
 
 }  // namespace webrtc
 #endif  // WEBRTC_VIDEO_RECEIVE_STATISTICS_PROXY_H_