Log MediaSource parsing errors to the MediaLog so they can appear in chrome:media-internals.

media/mp4/track_run_iterator.h

Index: media/mp4/track_run_iterator.h
diff --git a/media/mp4/track_run_iterator.h b/media/mp4/track_run_iterator.h
index 85cadce568aeb0383c713d3de16bca9f45b54c7e..1e083ca6ed69186d66604cd5ae66184abc5eefa5 100644
--- a/media/mp4/track_run_iterator.h
+++ b/media/mp4/track_run_iterator.h
@@ -10,6 +10,7 @@
 #include "base/memory/scoped_ptr.h"
 #include "base/time.h"
 #include "media/base/media_export.h"
+#include "media/base/media_log.h"
 #include "media/mp4/box_definitions.h"
 #include "media/mp4/cenc.h"
 
@@ -29,7 +30,7 @@ class MEDIA_EXPORT TrackRunIterator {
  public:
   // Create a new TrackRunIterator. A reference to |moov| will be retained for
   // the lifetime of this object.
-  explicit TrackRunIterator(const Movie* moov);
+  TrackRunIterator(const Movie* moov, const LogCB& log_cb);
   ~TrackRunIterator();
 
   void Reset();
@@ -92,6 +93,7 @@ class MEDIA_EXPORT TrackRunIterator {
   const TrackEncryption& track_encryption() const;
 
   const Movie* moov_;
+  LogCB log_cb_;
 
   std::vector<TrackRunInfo> runs_;
   std::vector<TrackRunInfo>::const_iterator run_itr_;