Clean up RTCVideoFrame

webrtc/sdk/objc/Framework/Classes/RTCVideoFrame+Private.h

 /*
  *  Copyright 2015 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.
  */
 
 #import "WebRTC/RTCVideoFrame.h"
 
 #include "webrtc/api/video/video_frame_buffer.h"
-#include "webrtc/api/video/video_rotation.h"
 
 NS_ASSUME_NONNULL_BEGIN
 
 @interface RTCVideoFrame ()
 
-@property(nonatomic, readonly)
-    rtc::scoped_refptr<webrtc::VideoFrameBuffer> i420Buffer;
-
 - (instancetype)initWithVideoBuffer:
                     (rtc::scoped_refptr<webrtc::VideoFrameBuffer>)videoBuffer
-                           rotation:(webrtc::VideoRotation)rotation
+                           rotation:(RTCVideoRotation)rotation
                         timeStampNs:(int64_t)timeStampNs
     NS_DESIGNATED_INITIALIZER;
 
 @end
 
 NS_ASSUME_NONNULL_END