Convert MediaLog from being ref counted to owned by WebMediaPlayer.

media/filters/decoder_stream.h

Index: media/filters/decoder_stream.h
diff --git a/media/filters/decoder_stream.h b/media/filters/decoder_stream.h
index 0056269389290bcec15ae01cfe81af0cf3e59bb5..e0f26c97c1ec2c6580e5f62c994b6f10d5fa2085 100644
--- a/media/filters/decoder_stream.h
+++ b/media/filters/decoder_stream.h
@@ -56,10 +56,9 @@ class MEDIA_EXPORT DecoderStream {
   // Indicates completion of a DecoderStream read.
   typedef base::Callback<void(Status, const scoped_refptr<Output>&)> ReadCB;
 
-  DecoderStream(
-      const scoped_refptr<base::SingleThreadTaskRunner>& task_runner,
-      ScopedVector<Decoder> decoders,
-      const scoped_refptr<MediaLog>& media_log);
+  DecoderStream(const scoped_refptr<base::SingleThreadTaskRunner>& task_runner,
+                ScopedVector<Decoder> decoders,
+                MediaLog* media_log);
   virtual ~DecoderStream();
 
   // Returns the string representation of the StreamType for logging purpose.
@@ -187,7 +186,7 @@ class MEDIA_EXPORT DecoderStream {
 
   scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
 
-  scoped_refptr<MediaLog> media_log_;
+  MediaLog* media_log_;
 
   State state_;