ObjC: RTCVideoSource cleanup

webrtc/sdk/objc/Framework/Classes/objcvideotracksource.h

 /*
  *  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.
  */
 
 #ifndef WEBRTC_SDK_OBJC_FRAMEWORK_CLASSES_OBJCVIDEOTRACKSOURCE_H_
 #define WEBRTC_SDK_OBJC_FRAMEWORK_CLASSES_OBJCVIDEOTRACKSOURCE_H_
 
-#import <WebRTC/RTCVideoFrame.h>
-
+#include "WebRTC/RTCMacros.h"
 #include "webrtc/base/timestampaligner.h"
 #include "webrtc/media/base/adaptedvideotracksource.h"
 
+RTC_FWD_DECL_OBJC_CLASS(RTCVideoFrame);
+
 namespace webrtc {
 
 class ObjcVideoTrackSource : public rtc::AdaptedVideoTrackSource {
  public:
   ObjcVideoTrackSource();
 
   // This class can not be used for implementing screen casting. Hopefully, this
   // function will be removed before we add that to iOS/Mac.
   bool is_screencast() const override { return false; }
 
@@ skipping 13 matching lines @@
   void OnOutputFormatRequest(int width, int height, int fps);
 
  private:
   rtc::VideoBroadcaster broadcaster_;
   rtc::TimestampAligner timestamp_aligner_;
 };
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_SDK_OBJC_FRAMEWORK_CLASSES_OBJCVIDEOTRACKSOURCE_H_