Fix memory leak in VideoToolbox encoder.

webrtc/sdk/objc/Framework/Classes/VideoToolbox/objc_video_encoder_factory.mm

 /*
  *  Copyright 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.
  */
 
@@ skipping 60 matching lines @@
 
       // Handle types than can be converted into one of CodecSpecificInfo's hard coded cases.
       CodecSpecificInfo codecSpecificInfo;
       if ([info isKindOfClass:[RTCCodecSpecificInfoH264 class]]) {
         codecSpecificInfo = [(RTCCodecSpecificInfoH264 *)info nativeCodecSpecificInfo];
       }
 
       std::unique_ptr<RTPFragmentationHeader> fragmentationHeader =
           [header createNativeFragmentationHeader];
       EncodedImageCallback::Result res =
-          callback->OnEncodedImage(encodedImage, &codecSpecificInfo, fragmentationHeader.release());
+          callback->OnEncodedImage(encodedImage, &codecSpecificInfo, fragmentationHeader.get());
       return res.error == EncodedImageCallback::Result::OK;
     }];
 
     return WEBRTC_VIDEO_CODEC_OK;
   }
 
   int32_t Release() { return [encoder_ releaseEncoder]; }
 
   int32_t Encode(const VideoFrame &frame,
                  const CodecSpecificInfo *codec_specific_info,
@@ skipping 66 matching lines @@
 
   return supported_codecs_;
 }
 
 void ObjCVideoEncoderFactory::DestroyVideoEncoder(VideoEncoder *encoder) {
   delete encoder;
   encoder = nullptr;
 }
 
 }  // namespace webrtc