Attach (recommended) or Link to PDF file here:
[multiple.pdf](https://github.com/mozilla/pdf.js/files/6344777/multiple.pdf)

Steps to reproduce the problem:
1. Write something in a field

What is the expected behavior? (add screenshot)
The 3 fields must have the same value

What went wrong? (add screenshot)
The 2 other fields are empty

The three fields share the same name `Text3`.
It works as expected in Adobe and Chrome.
case AnnotationType.SQUARE:
        return new SquareAnnotationElement(parameters);
      case AnnotationType.CIRCLE:
        return new CircleAnnotationElement(parameters);
      case AnnotationType.POLYLINE:
        return new PolylineAnnotationElement(parameters);
      case AnnotationType.CARET:
        return new CaretAnnotationElement(parameters);
      case AnnotationType.INK:
        return new InkAnnotationElement(parameters);
      case AnnotationType.POLYGON:
        return new PolygonAnnotationElement(parameters);
      case AnnotationType.HIGHLIGHT:
        return new HighlightAnnotationElement(parameters);
      case AnnotationType.UNDERLINE:
        return new UnderlineAnnotationElement(parameters);
      case AnnotationType.SQUIGGLY:
        return new SquigglyAnnotationElement(parameters);
      case AnnotationType.STRIKEOUT:
        return new StrikeOutAnnotationElement(parameters);
      case AnnotationType.STAMP:
        return new StampAnnotationElement(parameters);
      case AnnotationType.FILEATTACHMENT:
        return new FileAttachmentAnnotationElement(parameters);
      default:
        return new AnnotationElement(parameters);
    }
  }
}
class AnnotationElement {