Link to PDF file (or attach file here):
[pages4.pdf](https://github.com/mozilla/pdf.js/files/1128300/pages4.pdf)

Configuration:
- Web browser and its version: Firefox 54
- Operating system and its version: Win 10
- PDF.js version: 1.8.522
- Is an extension: no

What is the expected behavior? (add screenshot)
![chrome1-1 1](https://user-images.githubusercontent.com/146436/27918380-2f74512a-6245-11e7-8525-d0038fa6c2e8.jpg)
![chrome1-2 1](https://user-images.githubusercontent.com/146436/27918425-54f8e47e-6245-11e7-9bff-127f79ad0511.jpg)


What went wrong? (add screenshot)
![screenshot from 2017-07-06 12-10-30](https://user-images.githubusercontent.com/146436/27918442-5d57624e-6245-11e7-9436-5ba31cc8bd1a.png)
![screenshot from 2017-07-06 12-10-44](https://user-images.githubusercontent.com/146436/27918454-63b486da-6245-11e7-9eb5-c03aa5c40943.png)



if (URL.createObjectURL && typeof Blob !== "undefined" && !forceDataSchema) {
    return URL.createObjectURL(new Blob([data], { type: contentType }));
  }
  
  const digits =
    "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
  let buffer = `data:${contentType};base64,`;
  for (let i = 0, ii = data.length; i < ii; i += 3) {
    const b1 = data[i] & 0xff;
    const b2 = data[i + 1] & 0xff;
    const b3 = data[i + 2] & 0xff;
    const d1 = b1 >> 2,
      d2 = ((b1 & 3) << 4) | (b2 >> 4);
    const d3 = i + 1 < ii ? ((b2 & 0xf) << 2) | (b3 >> 6) : 64;
    const d4 = i + 2 < ii ? b3 & 0x3f : 64;
    buffer += digits[d1] + digits[d2] + digits[d3] + digits[d4];
  }
  return buffer;
}
export {
  AbortException,
  AnnotationActionEventType,
  AnnotationBorderStyleType,
  AnnotationFieldFlag,
  AnnotationFlag,
  AnnotationMarkedState,
  AnnotationMode,
  AnnotationReplyType,
  AnnotationReviewState,