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

media/webm/webm_cluster_parser.h

Index: media/webm/webm_cluster_parser.h
diff --git a/media/webm/webm_cluster_parser.h b/media/webm/webm_cluster_parser.h
index 6748a28ed1563812077e5ebf2c8ace50a55988e7..f31a0cb7d06ebe5319ab805515b4ae0513f001ff 100644
--- a/media/webm/webm_cluster_parser.h
+++ b/media/webm/webm_cluster_parser.h
@@ -10,6 +10,7 @@
 
 #include "base/memory/scoped_ptr.h"
 #include "media/base/media_export.h"
+#include "media/base/media_log.h"
 #include "media/base/stream_parser_buffer.h"
 #include "media/webm/webm_parser.h"
 
@@ -23,7 +24,8 @@ class MEDIA_EXPORT WebMClusterParser : public WebMParserClient {
                     int audio_track_num,
                     int video_track_num,
                     const std::string& audio_encryption_key_id,
-                    const std::string& video_encryption_key_id);
+                    const std::string& video_encryption_key_id,
+                    const LogCB& log_cb);
   virtual ~WebMClusterParser();
 
   // Resets the parser state so it can accept a new cluster.
@@ -92,6 +94,8 @@ class MEDIA_EXPORT WebMClusterParser : public WebMParserClient {
   Track audio_;
   Track video_;
 
+  LogCB log_cb_;
+
   DISALLOW_IMPLICIT_CONSTRUCTORS(WebMClusterParser);
 };