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

media/base/stream_parser.cc

Index: media/base/stream_parser.cc
diff --git a/media/base/stream_parser.cc b/media/base/stream_parser.cc
index f63644a7755061ddca1800f73f0863b658fd97de..9f3119b33b004e0eb27366d223595587d35e7473 100644
--- a/media/base/stream_parser.cc
+++ b/media/base/stream_parser.cc
@@ -11,8 +11,10 @@ namespace media {
 StreamParser::InitParameters::InitParameters(base::TimeDelta duration)
     : duration(duration),
       auto_update_timestamp_offset(false),
-      liveness(DemuxerStream::LIVENESS_UNKNOWN) {
-}
+      liveness(DemuxerStream::LIVENESS_UNKNOWN),
+      detected_audio_track_count(0),
+      detected_video_track_count(0),
+      detected_text_track_count(0) {}
 
 StreamParser::StreamParser() {}