Convert MediaLog from being ref counted to owned by WebMediaPlayer.

media/filters/decoder_selector.h

Index: media/filters/decoder_selector.h
diff --git a/media/filters/decoder_selector.h b/media/filters/decoder_selector.h
index 09378b86c113745a5b9cbb6ba0f7b5235665f426..3ce4df6b201333d54617973dc02c8f7043a53598 100644
--- a/media/filters/decoder_selector.h
+++ b/media/filters/decoder_selector.h
@@ -56,7 +56,7 @@ class MEDIA_EXPORT DecoderSelector {
   DecoderSelector(
       const scoped_refptr<base::SingleThreadTaskRunner>& message_loop,
       ScopedVector<Decoder> decoders,
-      const scoped_refptr<MediaLog>& media_log);
+      MediaLog* media_log);
 
   // Aborts pending Decoder selection and fires |select_decoder_cb| with
   // NULL and NULL immediately if it's pending.
@@ -91,7 +91,7 @@ class MEDIA_EXPORT DecoderSelector {
 
   scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
   ScopedVector<Decoder> decoders_;
-  scoped_refptr<MediaLog> media_log_;
+  MediaLog* media_log_;
 
   StreamTraits* traits_;