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 dict = xref.fetchIfRef(ref);
    if (!isDict(dict)) {
      return undefined;
    }
    const id = isRef(ref) ? ref.toString() : `annot_${idFactory.createObjId()}`;
    
    let subtype = dict.get("Subtype");
    subtype = isName(subtype) ? subtype.name : null;
    
    const parameters = {
      xref,
      ref,
      dict,
      subtype,
      id,
      pdfManager,
      acroForm: acroForm instanceof Dict ? acroForm : Dict.empty,
    };
    switch (subtype) {
      case "Link":
        return new LinkAnnotation(parameters);
      case "Text":
        return new TextAnnotation(parameters);
      case "Widget":
        let fieldType = getInheritableProperty({ dict, key: "FT" });
        fieldType = isName(fieldType) ? fieldType.name : null;
        switch (fieldType) {