Added debug logging for MSE config changes.

media/filters/chunk_demuxer.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef MEDIA_FILTERS_CHUNK_DEMUXER_H_
 #define MEDIA_FILTERS_CHUNK_DEMUXER_H_
 
 #include <map>
 #include <string>
 #include <utility>
@@ skipping 156 matching lines @@
 
   // Returns the ranges representing the buffered data in the demuxer.
   Ranges<base::TimeDelta> GetBufferedRanges() const;
 
   mutable base::Lock lock_;
   State state_;
 
   DemuxerHost* host_;
   base::Closure open_cb_;
   NeedKeyCB need_key_cb_;
+  // Callback used to report error strings that can help the web developer

[ddorwin, 2013/01/07 19:04:24]

Copied this from sourc_buffer_stream.h. It's not obvious in the .cc files that
these will all be reported as errors. It would be nice to report info/events
too. (Instead, I had to DVLOG(). I considered renaming this member to
log_error_cb_ to address the .cc issue. I don't think it should increase the
number of lines required, but I didn't want to make a bunch of changes without
buy-in.

[acolwell GONE FROM CHROMIUM, 2013/01/07 19:27:35]

This isn't intended to only log errors. I don't think we should rename this
especially since scherkus@ had me remove error from the name before checkin. If
the word error in MediaLogEvent::MEDIA_SOURCE_ERROR is troubling you, then I'd
suggest removing that instead of adding error here.

I'm wary of reporting tons of stuff through this mechanism. If our code is
working properly, the web developer doesn't need to know when the config change
is actually processed by the media engine.

+  // figure out what is wrong with the content.
   LogCB log_cb_;
 
   PipelineStatusCB init_cb_;
   PipelineStatusCB seek_cb_;
 
   scoped_refptr<ChunkDemuxerStream> audio_;
   scoped_refptr<ChunkDemuxerStream> video_;
 
   base::TimeDelta duration_;
 
@@ skipping 13 matching lines @@
   // removed with RemoveID() but can not be re-added (yet).
   std::string source_id_audio_;
   std::string source_id_video_;
 
   DISALLOW_COPY_AND_ASSIGN(ChunkDemuxer);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_FILTERS_CHUNK_DEMUXER_H_