Guard against midstream audio configuration 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 1f091c377acb288adf9788117f0425748b6c371d..8162bbf6458b1b55ead2dc146a32662c2a520c00 100644
--- a/media/filters/chunk_demuxer.cc
+++ b/media/filters/chunk_demuxer.cc
@@ -218,7 +218,7 @@ class ChunkDemuxerStream : public DemuxerStream {
   // Append() belong to a media segment that starts at |start_timestamp|.
   void OnNewMediaSegment(TimeDelta start_timestamp);
 
-  // Called when mid-stream config updates occur.
+  // Called when midstream config updates occur.
   // Returns true if the new config is accepted.
   // Returns false if the new config should trigger an error.
   bool UpdateAudioConfig(const AudioDecoderConfig& config);