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">


const strokeColor = this.color
          ? Array.from(this.color).map(c => c / 255)
          : [0, 0, 0];
        this._setDefaultAppearance({
          xref: parameters.xref,
          extra: "[] 0 d 1 w",
          strokeColor,
          pointsCallback: (buffer, points) => {
            const dy = (points[0].y - points[2].y) / 6;
            let shift = dy;
            let x = points[2].x;
            const y = points[2].y;
            const xEnd = points[3].x;
            buffer.push(`${x} ${y + shift} m`);
            do {
              x += 2;
              shift = shift === 0 ? dy : 0;
              buffer.push(`${x} ${y + shift} l`);
            } while (x < xEnd);
            buffer.push("S");
            return [points[2].x, xEnd, y - 2 * dy, y + 2 * dy];
          },
        });
      }
    } else {
      this.data.hasPopup = false;
    }
  }
}
class StrikeOutAnnotation extends MarkupAnnotation {