Added debug logging for MSE config changes.

media/filters/chunk_demuxer.cc

Index: media/filters/chunk_demuxer.cc
diff --git a/media/filters/chunk_demuxer.cc b/media/filters/chunk_demuxer.cc
index 092fa4f8b0f3b5bd46121d2a1b628343b64374d0..0df35513b490ee23f98e4c3eb3a6f3cef51a29a0 100644
--- a/media/filters/chunk_demuxer.cc
+++ b/media/filters/chunk_demuxer.cc
@@ -520,6 +520,7 @@ bool ChunkDemuxerStream::GetNextBuffer_Locked(
           }
           return false;
         case SourceBufferStream::kConfigChange:
+          DVLOG(2) << "Config change reported to ChunkDemuxerStream.";
           *status = kConfigChanged;
           *buffer = NULL;
           return true;
@@ -1118,7 +1119,7 @@ bool ChunkDemuxer::OnNewConfigs(bool has_audio, bool has_video,
     }
   }
 
-  DVLOG(1) << "OnNewConfigs() : success " << success;
+  DVLOG(1) << "OnNewConfigs() : " << (success ? "success" : "failed");
   return success;
 }