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,
    {
      isRenderable = false,
      ignoreBorder = false,
      createQuadrilaterals = false,
    } = {}
  ) {
    this.isRenderable = isRenderable;
    this.data = parameters.data;
    this.layer = parameters.layer;
    this.page = parameters.page;
    this.viewport = parameters.viewport;
    this.linkService = parameters.linkService;
    this.downloadManager = parameters.downloadManager;
    this.imageResourcesPath = parameters.imageResourcesPath;
    this.renderInteractiveForms = parameters.renderInteractiveForms;
    this.svgFactory = parameters.svgFactory;
    this.annotationStorage = parameters.annotationStorage;
    this.enableScripting = parameters.enableScripting;
    this.hasJSActions = parameters.hasJSActions;
    this._mouseState = parameters.mouseState;
    if (isRenderable) {
      this.container = this._createContainer(ignoreBorder);
    }