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)



const length = str.length,
    strBuf = [];
  if (str[0] === "\xFE" && str[1] === "\xFF") {
    
    for (let i = 2; i < length; i += 2) {
      strBuf.push(
        String.fromCharCode((str.charCodeAt(i) << 8) | str.charCodeAt(i + 1))
      );
    }
  } else if (str[0] === "\xFF" && str[1] === "\xFE") {
    
    for (let i = 2; i < length; i += 2) {
      strBuf.push(
        String.fromCharCode((str.charCodeAt(i + 1) << 8) | str.charCodeAt(i))
      );
    }
  } else {
    for (let i = 0; i < length; ++i) {
      const code = PDFStringTranslateTable[str.charCodeAt(i)];
      strBuf.push(code ? String.fromCharCode(code) : str.charAt(i));
    }
  }
  return strBuf.join("");
}
function escapeString(str) {