Convert MediaLog from being ref counted to owned by WebMediaPlayer.

media/formats/mp4/mp4_stream_parser.h

Index: media/formats/mp4/mp4_stream_parser.h
diff --git a/media/formats/mp4/mp4_stream_parser.h b/media/formats/mp4/mp4_stream_parser.h
index c0997435be6aca7afe8d5410e0437b8c604be69c..888cf3051aecd2f7708e15069d80f947a2814f9c 100644
--- a/media/formats/mp4/mp4_stream_parser.h
+++ b/media/formats/mp4/mp4_stream_parser.h
@@ -37,7 +37,7 @@ class MEDIA_EXPORT MP4StreamParser : public StreamParser {
             const EncryptedMediaInitDataCB& encrypted_media_init_data_cb,
             const NewMediaSegmentCB& new_segment_cb,
             const EndMediaSegmentCB& end_of_segment_cb,
-            const scoped_refptr<MediaLog>& media_log) override;
+            MediaLog* media_log) override;
   void Flush() override;
   bool Parse(const uint8_t* buf, int size) override;
 
@@ -94,7 +94,7 @@ class MEDIA_EXPORT MP4StreamParser : public StreamParser {
   EncryptedMediaInitDataCB encrypted_media_init_data_cb_;
   NewMediaSegmentCB new_segment_cb_;
   EndMediaSegmentCB end_of_segment_cb_;
-  scoped_refptr<MediaLog> media_log_;
+  MediaLog* media_log_;
 
   OffsetByteQueue queue_;