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 (isNum(glyph)) {
        spacingLength = (spacingDir * glyph * fontSize) / 1000;
        this.ctx.translate(spacingLength, 0);
        current.x += spacingLength * textHScale;
        continue;
      }
      const spacing = (glyph.isSpace ? wordSpacing : 0) + charSpacing;
      const operatorList = font.charProcOperatorList[glyph.operatorListId];
      if (!operatorList) {
        warn(`Type3 character "${glyph.operatorListId}" is not available.`);
        continue;
      }
      if (this.contentVisible) {
        this.processingType3 = glyph;
        this.save();
        ctx.scale(fontSize, fontSize);
        ctx.transform.apply(ctx, fontMatrix);
        this.executeOperatorList(operatorList);
        this.restore();
      }
      const transformed = Util.applyTransform([glyph.width, 0], fontMatrix);
      width = transformed[0] * fontSize + spacing;
      ctx.translate(width, 0);
      current.x += width * textHScale;
    }
    ctx.restore();
    this.processingType3 = null;
  }
  
  setCharWidth(xWidth, yWidth) {