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">


event.target.title = detail.userName;
            },
            hidden() {
              event.target.style.visibility = detail.hidden
                ? "hidden"
                : "visible";
              storage.setValue(id, { hidden: detail.hidden });
            },
            editable() {
              event.target.disabled = !detail.editable;
            },
            selRange() {
              const [selStart, selEnd] = detail.selRange;
              if (selStart >= 0 && selEnd < event.target.value.length) {
                event.target.setSelectionRange(selStart, selEnd);
              }
            },
            strokeColor() {
              const color = detail.strokeColor;
              event.target.style.color = ColorConverters[`${color[0]}_HTML`](
                color.slice(1)
              );
            },
          };
          Object.keys(detail)
            .filter(name => name in actions)
            .forEach(name => actions[name]());
        });