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">


constructor(parameters) {
    super(parameters);
    const dict = parameters.dict;
    if (dict.has("IRT")) {
      const rawIRT = dict.getRaw("IRT");
      this.data.inReplyTo = isRef(rawIRT) ? rawIRT.toString() : null;
      const rt = dict.get("RT");
      this.data.replyType = isName(rt) ? rt.name : AnnotationReplyType.REPLY;
    }
    if (this.data.replyType === AnnotationReplyType.GROUP) {
      
      
      const parent = dict.get("IRT");
      this.data.title = stringToPDFString(parent.get("T") || "");
      this.setContents(parent.get("Contents"));
      this.data.contents = this.contents;
      if (!parent.has("CreationDate")) {
        this.data.creationDate = null;
      } else {
        this.setCreationDate(parent.get("CreationDate"));
        this.data.creationDate = this.creationDate;
      }
      if (!parent.has("M")) {
        this.data.modificationDate = null;
      } else {
        this.setModificationDate(parent.get("M"));