Convert MediaLog from being ref counted to owned by WebMediaPlayer.

media/formats/webm/webm_stream_parser.h

Index: media/formats/webm/webm_stream_parser.h
diff --git a/media/formats/webm/webm_stream_parser.h b/media/formats/webm/webm_stream_parser.h
index 0259e083302d7945daa3e6168ec27bf5340cb36f..bc79c6053266b6ad1fd81373a8d0db507710c4aa 100644
--- a/media/formats/webm/webm_stream_parser.h
+++ b/media/formats/webm/webm_stream_parser.h
@@ -35,7 +35,7 @@ class MEDIA_EXPORT WebMStreamParser : 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;
 
@@ -80,7 +80,7 @@ class MEDIA_EXPORT WebMStreamParser : public StreamParser {
 
   NewMediaSegmentCB new_segment_cb_;
   EndMediaSegmentCB end_of_segment_cb_;
-  scoped_refptr<MediaLog> media_log_;
+  MediaLog* media_log_;
 
   bool unknown_segment_size_;