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">


return newRefs;
  }
  _processCheckBox(params) {
    const customAppearance = params.dict.get("AP");
    if (!isDict(customAppearance)) {
      return;
    }
    const normalAppearance = customAppearance.get("N");
    if (!isDict(normalAppearance)) {
      return;
    }
    const exportValues = normalAppearance.getKeys();
    if (!exportValues.includes("Off")) {
      
      exportValues.push("Off");
    }
    if (exportValues.length !== 2) {
      return;
    }
    this.data.exportValue =
      exportValues[0] === "Off" ? exportValues[1] : exportValues[0];
    this.checkedAppearance = normalAppearance.get(this.data.exportValue);
    this.uncheckedAppearance = normalAppearance.get("Off") || null;
    this._streams.push(this.checkedAppearance);
    if (this.uncheckedAppearance) {
      this._streams.push(this.uncheckedAppearance);
    }
    this._fallbackFontDict = this.fallbackFontDict;
  }
  _processRadioButton(params) {