MSE: Record counts of detected MSE audio, video and text tracks

media/base/stream_parser.h

Index: media/base/stream_parser.h
diff --git a/media/base/stream_parser.h b/media/base/stream_parser.h
index 4b9fa7f3e4d314f1616907c8bd1d2af16131cb6c..bae340aa64a64df5f0d84f5acf293e8eb455cd68 100644
--- a/media/base/stream_parser.h
+++ b/media/base/stream_parser.h
@@ -68,6 +68,12 @@ class MEDIA_EXPORT StreamParser {
 
     // Indicates live stream.
     DemuxerStream::Liveness liveness;
+
+    // Counts of tracks detected by type within this stream. Not all of these
+    // tracks may be selected for use by the parser.
+    int detected_audio_track_count;
+    int detected_video_track_count;
+    int detected_text_track_count;
   };
 
   // Indicates completion of parser initialization.
@@ -77,9 +83,9 @@ class MEDIA_EXPORT StreamParser {
   // Indicates when new stream configurations have been parsed.
   // First parameter - An object containing information about media tracks as
   //                   well as audio/video decoder configs associated with each
-  //                   track.
+  //                   track the parser will use from the stream.
   // Second parameter - The new text tracks configuration.  If the map is empty,
-  //                    then no text tracks were parsed from the stream.
+  //                    then no text tracks were parsed for use from the stream.
   // Return value - True if the new configurations are accepted.
   //                False if the new configurations are not supported
   //                and indicates that a parsing error should be signalled.