Fix memory leak in VideoToolbox encoder.

webrtc/sdk/objc/Framework/Classes/VideoToolbox/nalu_rewriter.h

Index: webrtc/sdk/objc/Framework/Classes/VideoToolbox/nalu_rewriter.h
diff --git a/webrtc/sdk/objc/Framework/Classes/VideoToolbox/nalu_rewriter.h b/webrtc/sdk/objc/Framework/Classes/VideoToolbox/nalu_rewriter.h
index 4685f08757256c51a2a86c1560bfa433e15305ae..3d7a88ffc5230de5f4c9f912e714149d6738c608 100644
--- a/webrtc/sdk/objc/Framework/Classes/VideoToolbox/nalu_rewriter.h
+++ b/webrtc/sdk/objc/Framework/Classes/VideoToolbox/nalu_rewriter.h
@@ -33,7 +33,7 @@ bool H264CMSampleBufferToAnnexBBuffer(
     CMSampleBufferRef avcc_sample_buffer,
     bool is_keyframe,
     rtc::Buffer* annexb_buffer,
-    webrtc::RTPFragmentationHeader** out_header);
+    std::unique_ptr<RTPFragmentationHeader> *out_header);
 
 // Converts a buffer received from RTP into a sample buffer suitable for the
 // VideoToolbox decoder. The RTP buffer is in annex b format whereas the sample