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">


elementData.userValue = detail.value || "";
              storage.setValue(id, { value: elementData.userValue.toString() });
              if (!elementData.formattedValue) {
                event.target.value = elementData.userValue;
              }
            },
            valueAsString() {
              elementData.formattedValue = detail.valueAsString || "";
              if (event.target !== document.activeElement) {
                
                event.target.value = elementData.formattedValue;
              }
              storage.setValue(id, {
                formattedValue: elementData.formattedValue,
              });
            },
            focus() {
              setTimeout(() => event.target.focus({ preventScroll: false }), 0);
            },
            userName() {