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">


lastSpacePosInStringStart = start;
          lastSpacePosInStringEnd = end;
          lastSpacePos = i;
        }
      } else {
        if (currentWidth + glyphWidth > width) {
          
          if (lastSpacePosInStringStart !== -1) {
            chunks.push(line.substring(startChunk, lastSpacePosInStringEnd));
            startChunk = lastSpacePosInStringEnd;
            i = lastSpacePos + 1;
            lastSpacePosInStringStart = -1;
            currentWidth = 0;
          } else {
            
            chunks.push(line.substring(startChunk, start));
            startChunk = start;
            currentWidth = glyphWidth;
          }
        } else {
          currentWidth += glyphWidth;
        }
      }
    }
    if (startChunk < line.length) {
      chunks.push(line.substring(startChunk, line.length));
    }
    return chunks;
  }
  getFieldObject() {