function showPlaybackRateOverlay(player, newRate, isSpeedUp) {
  const overlayJsx = (
    <div>
      <p>{newRate}x</p>
      <p>
        <Icon icon={isSpeedUp ? ICONS.ARROW_RIGHT : ICONS.ARROW_LEFT} size={48} />
      </p>
    </div>
  );

  showOneOffOverlay(player, OVERLAY_CLASS_PLAYBACK_RATE, overlayJsx, 'center');
}
Displays a transient "Playback Rate" overlay.

@param player The videojs instance.
@param newRate The current playback rate value.
@param isSpeedUp true if the change was speeding up, false otherwise.