test/trace_processor/track_event_typed_args.textproto

packet {
  trusted_packet_sequence_id: 1
  timestamp: 0
  incremental_state_cleared: true
  track_descriptor {
    uuid: 1
    thread {
      pid: 5
      tid: 1
      thread_name: "t1"
    }
  }
}
packet {
  trusted_packet_sequence_id: 1
  timestamp: 1000
  track_event {
    track_uuid: 1
    categories: "cat"
    name: "name1"
    type: 3
    chrome_user_event {
      action: "NewTab"
    }
  }
}
packet {
  trusted_packet_sequence_id: 1
  timestamp: 2000
  track_event {
    track_uuid: 1
    categories: "cat"
    name: "name2"
    type: 3
    chrome_legacy_ipc {
      message_class: 1
      message_line: 10
    }
  }
}
packet {
  trusted_packet_sequence_id: 1
  timestamp: 3000
  track_event {
    track_uuid: 1
    categories: "cat"
    name: "name3"
    type: 3
    chrome_keyed_service {
      name: "MediaRouter"
    }
  }
}