readTerminatedString() {
    const start = this.position_;
    while (this.hasMoreData()) {
      const value = this.dataView_.getUint8(this.position_);
      if (value == 0) {
        break;
      }
      this.position_ += 1;
    }

    const ret = shaka.util.BufferUtils.toUint8(
        this.dataView_, start, this.position_ - start);
    // Skip string termination.
    this.position_ += 1;
    return shaka.util.StringUtils.fromUTF8(ret);
  }
Keeps reading until it reaches a byte that equals to zero.  The text is
assumed to be UTF-8.
@return {string}
@export