Move optional.h to webrtc/api/

webrtc/rtc_base/rtccertificategenerator_unittest.cc

 /*
  *  Copyright 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 "webrtc/rtc_base/rtccertificategenerator.h"
 
 #include <memory>
 
+#include "webrtc/api/optional.h"
 #include "webrtc/rtc_base/checks.h"
 #include "webrtc/rtc_base/gunit.h"
 #include "webrtc/rtc_base/logging.h"
-#include "webrtc/rtc_base/optional.h"
 #include "webrtc/rtc_base/thread.h"
 
 namespace rtc {
 
 class RTCCertificateGeneratorFixture : public RTCCertificateGeneratorCallback {
  public:
   RTCCertificateGeneratorFixture()
       : signaling_thread_(Thread::Current()),
         worker_thread_(Thread::Create()),
         generate_async_completed_(false) {
@@ skipping 114 matching lines @@
 
   fixture_->generator()->GenerateCertificateAsync(
       invalid_params,
       Optional<uint64_t>(),
       fixture_);
   EXPECT_TRUE_WAIT(fixture_->GenerateAsyncCompleted(), kGenerationTimeoutMs);
   EXPECT_FALSE(fixture_->certificate());
 }
 
 }  // namespace rtc