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">


if (this.data.actions) {
          
          
          element.addEventListener("keydown", event => {
            elementData.beforeInputValue = event.target.value;
            
            
            let commitKey = -1;
            if (event.key === "Escape") {
              commitKey = 0;
            } else if (event.key === "Enter") {
              commitKey = 2;
            } else if (event.key === "Tab") {
              commitKey = 3;
            }
            if (commitKey === -1) {
              return;
            }
            
            elementData.userValue = event.target.value;
            this.linkService.eventBus?.dispatch("dispatcheventinsandbox", {
              source: this,
              detail: {
                id,
                name: "Keystroke",
                value: event.target.value,
                willCommit: true,
                commitKey,
                selStart: event.target.selectionStart,
                selEnd: event.target.selectionEnd,