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 p0 = p;
    let type = points[p];
    do {
      const step = steps[type];
      do {
        p += step;
      } while (!points[p]);
      const pp = points[p];
      if (pp !== 5 && pp !== 10) {
        
        type = pp;
        
        points[p] = 0;
      } else {
        
        
        type = pp & ((0x33 * type) >> 4);
        
        points[p] &= (type >> 2) | (type << 2);
      }
      coords.push(p % width1, (p / width1) | 0);
      if (!points[p]) {
        --count;
      }
    } while (p0 !== p);
    outlines.push(coords);
    --i;
  }
  const drawOutline = function (c) {
    c.save();