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">


setTimeout(() => event.target.focus({ preventScroll: false }), 0);
          },
          hidden() {
            event.target.style.visibility = detail.hidden
              ? "hidden"
              : "visible";
            storage.setValue(id, { hidden: detail.hidden });
          },
          editable() {
            event.target.disabled = !detail.editable;
          },
        };
        Object.keys(detail)
          .filter(name => name in actions)
          .forEach(name => actions[name]());
      });
      selectElement.addEventListener("input", event => {
        const value = getValue(event);
        storage.setValue(id, { value });
        this.linkService.eventBus?.dispatch("dispatcheventinsandbox", {
          source: this,
          detail: {
            id,
            name: "Keystroke",
            changeEx: value,
            willCommit: true,
            commitKey: 1,
            keyDown: false,