Attach (recommended) or Link to PDF file here:
issue13500 (in test corpus)

This regressed when landing #13566. 

What is the expected behavior? (add screenshot)
<img width="664" alt="image" src="https://user-images.githubusercontent.com/942640/122467522-7bc8aa80-cf6f-11eb-9d4d-311eb7c64fb2.png">


What went wrong? (add screenshot)
![image](https://user-images.githubusercontent.com/942640/122467565-85eaa900-cf6f-11eb-9c10-8a8686ed440c.png)


if (this.href || !this[$content]) {
      
      
      
      
      return HTMLResult.EMPTY;
    }
    
    if (this.transferEncoding === "base64") {
      const buffer = stringToBytes(atob(this[$content]));
      const blob = new Blob([buffer], { type: this.contentType });
      return HTMLResult.success({
        name: "img",
        attributes: {
          class: ["xfaImage"],
          style: {},
          src: URL.createObjectURL(blob),
        },
      });
    }
    return HTMLResult.EMPTY;
  }
}
class ImageEdit extends XFAObject {