Convert MediaLog from being ref counted to owned by WebMediaPlayer.

media/filters/audio_decoder_unittest.cc

Index: media/filters/audio_decoder_unittest.cc
diff --git a/media/filters/audio_decoder_unittest.cc b/media/filters/audio_decoder_unittest.cc
index 414cd15ac736dc5ed6c77ea3093f191b78fb9226..535685678ffdb24bb27221468d5f83f16546cb90 100644
--- a/media/filters/audio_decoder_unittest.cc
+++ b/media/filters/audio_decoder_unittest.cc
@@ -131,8 +131,8 @@ class AudioDecoderTest
         last_decode_status_(DecodeStatus::DECODE_ERROR) {
     switch (decoder_type_) {
       case FFMPEG:
-        decoder_.reset(new FFmpegAudioDecoder(message_loop_.task_runner(),
-                                              new MediaLog()));
+        decoder_.reset(
+            new FFmpegAudioDecoder(message_loop_.task_runner(), &media_log_));
         break;
 #if defined(OS_ANDROID)
       case MEDIA_CODEC:
@@ -391,6 +391,7 @@ class AudioDecoderTest
 
   base::MessageLoop message_loop_;
 
+  MediaLog media_log_;
   scoped_refptr<DecoderBuffer> data_;
   std::unique_ptr<InMemoryUrlProtocol> protocol_;
   std::unique_ptr<AudioFileReader> reader_;