Attach (recommended) or Link to PDF file here:
https://drive.google.com/open?id=1UjLxnFw2g3gn3tvNLRYLdmG6mFdFKCcr

Configuration:
- Web browser and its version: Chrome 77.0.3865.90
- Operating system and its version: Mac mojave 10.14.6
- PDF.js version: 2.3.194
- Is a browser extension: Nope

Steps to reproduce the problem:
1. Make sure to set `renderInteractiveForms` to `true`
2. The read-only form field(Sample title) doesn't honor it's proper font-size

What is the expected behavior?
<img width="862" alt="write" src="https://user-images.githubusercontent.com/4616548/66152094-4a009a80-e64b-11e9-81dc-178068055efa.png">

What went wrong?
<img width="842" alt="wrong" src="https://user-images.githubusercontent.com/4616548/66152100-4d942180-e64b-11e9-91a8-ad9caf451f98.png">


for (const coordinate of data.vertices) {
      const x = coordinate.x - data.rect[0];
      const y = data.rect[3] - coordinate.y;
      points.push(x + "," + y);
    }
    points = points.join(" ");
    const polyline = this.svgFactory.createElement(this.svgElementName);
    polyline.setAttribute("points", points);
    
    
    polyline.setAttribute("stroke-width", data.borderStyle.width || 1);
    polyline.setAttribute("stroke", "transparent");
    polyline.setAttribute("fill", "none");
    svg.appendChild(polyline);
    this.container.append(svg);
    
    
    this._createPopup(polyline, data);
    return this.container;
  }
}
class PolygonAnnotationElement extends PolylineAnnotationElement {
  constructor(parameters) {
    
    super(parameters);
    this.containerClassName = "polygonAnnotation";
    this.svgElementName = "svg:polygon";
  }
}
class CaretAnnotationElement extends AnnotationElement {