Assign correct track ids to buffers emitted from StreamParsers

media/formats/mp2t/es_parser_mpeg1audio.cc

Index: media/formats/mp2t/es_parser_mpeg1audio.cc
diff --git a/media/formats/mp2t/es_parser_mpeg1audio.cc b/media/formats/mp2t/es_parser_mpeg1audio.cc
index 7cde8f80e1aafbc3eacab82da5488d70bf254c67..50cb1cb6a6623d509732facc917b4b5363e2db06 100644
--- a/media/formats/mp2t/es_parser_mpeg1audio.cc
+++ b/media/formats/mp2t/es_parser_mpeg1audio.cc
@@ -79,11 +79,9 @@ bool EsParserMpeg1Audio::ParseFromEsQueue() {
     // TODO(wolenetz/acolwell): Validate and use a common cross-parser TrackId
     // type and allow multiple audio tracks. See https://crbug.com/341581.
     scoped_refptr<StreamParserBuffer> stream_parser_buffer =
-        StreamParserBuffer::CopyFrom(
-            mpeg1audio_frame.data,
-            mpeg1audio_frame.size,
-            is_key_frame,
-            DemuxerStream::AUDIO, 0);
+        StreamParserBuffer::CopyFrom(mpeg1audio_frame.data,
+                                     mpeg1audio_frame.size, is_key_frame,
+                                     DemuxerStream::AUDIO, kMp2tAudioTrackId);
     stream_parser_buffer->set_timestamp(current_pts);
     stream_parser_buffer->set_duration(frame_duration);
     emit_buffer_cb_.Run(stream_parser_buffer);