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)



this.current.strokeColor = this.getColorN_Pattern(arguments);
  }
  setFillColorN() {
    this.current.fillColor = this.getColorN_Pattern(arguments);
    this.current.patternFill = true;
  }
  setStrokeRGBColor(r, g, b) {
    const color = Util.makeHexColor(r, g, b);
    this.ctx.strokeStyle = color;
    this.current.strokeColor = color;
  }
  setFillRGBColor(r, g, b) {
    const color = Util.makeHexColor(r, g, b);
    this.ctx.fillStyle = color;
    this.current.fillColor = color;
    this.current.patternFill = false;
  }
  _getPattern(objId, matrix = null) {