Move optional.h to webrtc/api/

webrtc/modules/audio_processing/level_controller/level_controller_unittest.cc

 /*
  *  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.
  */
 
 #include <vector>
 
 #include "webrtc/api/array_view.h"
+#include "webrtc/api/optional.h"
 #include "webrtc/modules/audio_processing/audio_buffer.h"
 #include "webrtc/modules/audio_processing/include/audio_processing.h"
 #include "webrtc/modules/audio_processing/level_controller/level_controller.h"
 #include "webrtc/modules/audio_processing/test/audio_buffer_tools.h"
 #include "webrtc/modules/audio_processing/test/bitexactness_tools.h"
-#include "webrtc/rtc_base/optional.h"
 #include "webrtc/test/gtest.h"
 
 namespace webrtc {
 namespace {
 
 const int kNumFramesToProcess = 1000;
 
 // Processes a specified amount of frames, verifies the results and reports
 // any errors.
 void RunBitexactnessTest(int sample_rate_hz,
@@ skipping 117 matching lines @@
                       rtc::Optional<float>(), kOutputReference);
 }
 
 TEST(LevelControlBitExactnessTest, DISABLED_MonoInitial48kHz) {
   const float kOutputReference[] = {-0.013753f, -0.014623f, -0.016797f};
   RunBitexactnessTest(AudioProcessing::kSampleRate48kHz, 1,
                       rtc::Optional<float>(-50), kOutputReference);
 }
 
 }  // namespace webrtc