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">


if (Array.isArray(formValue)) {
      return formValue
        .filter(item => isString(item))
        .map(item => stringToPDFString(item));
    } else if (isName(formValue)) {
      return stringToPDFString(formValue.name);
    } else if (isString(formValue)) {
      return stringToPDFString(formValue);
    }
    return null;
  }
  /**
   * Check if a provided field flag is set.
   *
   * @public
   * @memberof WidgetAnnotation
   * @param {number} flag - Hexadecimal representation for an annotation
   *                        field characteristic
   * @returns {boolean}
   * @see {@link shared/util.js}
   */
  hasFieldFlag(flag) {
    return !!(this.data.fieldFlags & flag);
  }
  getOperatorList(evaluator, task, renderForms, annotationStorage) {