Move optional.h to webrtc/api/

webrtc/modules/audio_coding/test/PCMFile.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_AUDIO_CODING_TEST_PCMFILE_H_
 #define WEBRTC_MODULES_AUDIO_CODING_TEST_PCMFILE_H_
 
 #include <stdio.h>
 #include <stdlib.h>
 
 #include <string>
 
+#include "webrtc/api/optional.h"
 #include "webrtc/modules/include/module_common_types.h"
-#include "webrtc/rtc_base/optional.h"
 #include "webrtc/typedefs.h"
 
 namespace webrtc {
 
 class PCMFile {
  public:
   PCMFile();
   PCMFile(uint32_t timestamp);
   ~PCMFile();
 
@@ skipping 36 matching lines @@
   uint32_t timestamp_;
   bool read_stereo_;
   bool save_stereo_;
   rtc::Optional<int> num_10ms_blocks_to_read_;
   int blocks_read_ = 0;
 };
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_MODULES_AUDIO_CODING_TEST_PCMFILE_H_