Move optional.h to webrtc/api/

webrtc/common_video/video_render_frames.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_COMMON_VIDEO_VIDEO_RENDER_FRAMES_H_
 #define WEBRTC_COMMON_VIDEO_VIDEO_RENDER_FRAMES_H_
 
 #include <stdint.h>
 
 #include <list>
 
+#include "webrtc/api/optional.h"
 #include "webrtc/api/video/video_frame.h"
-#include "webrtc/rtc_base/optional.h"
 
 namespace webrtc {
 
 // Class definitions
 class VideoRenderFrames {
  public:
   explicit VideoRenderFrames(uint32_t render_delay_ms);
   VideoRenderFrames(const VideoRenderFrames&) = delete;
 
   // Add a frame to the render queue
@@ skipping 13 matching lines @@
 
   // Estimated delay from a frame is released until it's rendered.
   const uint32_t render_delay_ms_;
 
   int64_t last_render_time_ms_ = 0;
 };
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_COMMON_VIDEO_VIDEO_RENDER_FRAMES_H_