Move optional.h to webrtc/api/

webrtc/modules/audio_processing/test/conversational_speech/generator_unittest.cc

 /*
  *  Copyright (c) 2017 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.
  */
 
@@ skipping 24 matching lines @@
 
 // MSVC++ requires this to be set before any other includes to get M_PI.
 #define _USE_MATH_DEFINES
 
 #include <stdio.h>
 #include <cmath>
 #include <map>
 #include <memory>
 #include <vector>
 
+#include "webrtc/api/optional.h"
 #include "webrtc/common_audio/wav_file.h"
 #include "webrtc/modules/audio_processing/test/conversational_speech/config.h"
 #include "webrtc/modules/audio_processing/test/conversational_speech/mock_wavreader_factory.h"
 #include "webrtc/modules/audio_processing/test/conversational_speech/multiend_call.h"
 #include "webrtc/modules/audio_processing/test/conversational_speech/simulator.h"
 #include "webrtc/modules/audio_processing/test/conversational_speech/timing.h"
 #include "webrtc/modules/audio_processing/test/conversational_speech/wavreader_factory.h"
 #include "webrtc/rtc_base/logging.h"
-#include "webrtc/rtc_base/optional.h"
 #include "webrtc/rtc_base/pathutils.h"
 #include "webrtc/test/gmock.h"
 #include "webrtc/test/gtest.h"
 #include "webrtc/test/testsupport/fileutils.h"
 
 namespace webrtc {
 namespace test {
 namespace {
 
 using conversational_speech::LoadTiming;
@@ skipping 615 matching lines @@
     CheckAudioTrackParams(
         wav_reader_factory, it.second.far_end, expeted_params);
   }
 
   // Clean.
   EXPECT_NO_FATAL_FAILURE(DeleteFolderAndContents(audiotracks_path));
 }
 
 }  // namespace test
 }  // namespace webrtc