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">


opList.addOp(OPS.beginAnnotation, [data.rect, transform, matrix]);
      return evaluator
        .getOperatorList({
          stream: appearance,
          task,
          resources,
          operatorList: opList,
          fallbackFontDict: this._fallbackFontDict,
        })
        .then(() => {
          opList.addOp(OPS.endAnnotation, []);
          this.reset();
          return opList;
        });
    });
  }
  async save(evaluator, task, annotationStorage) {
    return null;
  }
  /**
   * Get field data for usage in JS sandbox.
   *
   * Field object is defined here:
   * https://www.adobe.com/content/dam/acom/en/devnet/acrobat/pdfs/js_api_reference.pdf#page=16
   *
   * @public
   * @memberof Annotation
   * @returns {Object | null}
   */
  getFieldObject() {