Convert MediaLog from being ref counted to owned by WebMediaPlayer.

media/gpu/video_encode_accelerator_unittest.cc

Index: media/gpu/video_encode_accelerator_unittest.cc
diff --git a/media/gpu/video_encode_accelerator_unittest.cc b/media/gpu/video_encode_accelerator_unittest.cc
index b330202b13e3176e4828912d7d1f74e07da8cf21..2ee1df6e2cc4e56d1382b3d53d894cbed2a1e943 100644
--- a/media/gpu/video_encode_accelerator_unittest.cc
+++ b/media/gpu/video_encode_accelerator_unittest.cc
@@ -730,6 +730,7 @@ class VideoFrameQualityValidator
 
   enum State { UNINITIALIZED, INITIALIZED, DECODING, DECODER_ERROR };
 
+  MediaLog media_log_;
   const VideoCodecProfile profile_;
   std::unique_ptr<FFmpegVideoDecoder> decoder_;
   VideoDecoder::DecodeCB decode_cb_;
@@ -749,7 +750,7 @@ VideoFrameQualityValidator::VideoFrameQualityValidator(
     const base::Closure& flush_complete_cb,
     const base::Closure& decode_error_cb)
     : profile_(profile),
-      decoder_(new FFmpegVideoDecoder(make_scoped_refptr(new MediaLog()))),
+      decoder_(new FFmpegVideoDecoder(&media_log_)),
       decode_cb_(
           base::Bind(&VideoFrameQualityValidator::DecodeDone, AsWeakPtr())),
       eos_decode_cb_(