getFilteredTextTracks_() {
    goog.asserts.assert(this.video_.textTracks,
        'TextTracks should be valid.');
    return Array.from(this.video_.textTracks)
        .filter((t) => t.kind != 'metadata' && t.kind != 'chapters' &&
                       t.label != shaka.Player.TextTrackLabel);
  }
Ignore the TextTracks with the 'metadata' or 'chapters' kind, or the one
generated by the SimpleTextDisplayer.

@return {!Array<TextTrack>}
@private