Link to PDF file (or attach file here):
https://issues.apache.org/jira/secure/attachment/12650283/000004_ShadingPatternTextPDF.pdf

Configuration:
- Web browser and its version: FF 51.0.1 32bit
- Operating system and its version: W7
- PDF.js version: latest

Steps to reproduce the problem:
display file

What is the expected behavior? (add screenshot)
![ok](https://cloud.githubusercontent.com/assets/6665575/23339534/5ff2de9c-fc25-11e6-837e-0fdaf81b4ca9.png)

What went wrong? (add screenshot)
![nok](https://cloud.githubusercontent.com/assets/6665575/23339536/63f7a37e-fc25-11e6-813c-cc218cc4def3.png)

possibly similar problem:
https://www.pdflib.com/fileadmin/pdflib/Cookbook/pdf/color_gradient.pdf (shaded text completely missing)
https://issues.apache.org/jira/secure/attachment/12630566/pslib-shading.pdf (page 4, part of text missing)
https://issues.apache.org/jira/secure/attachment/12652009/pattern-shading-2-4-idMatrix.pdf (some text missing)
https://issues.apache.org/jira/secure/attachment/12652010/pattern-shading-2-4-noMatrix.pdf (some text missing)

y = args[j + 3];
          j += 4;
          break;
        case OPS.curveTo3:
          startX = x;
          startY = y;
          x = args[j + 2];
          y = args[j + 3];
          ctx.bezierCurveTo(args[j], args[j + 1], x, y, x, y);
          current.updateCurvePathMinMax(
            ctx.mozCurrentTransform,
            startX,
            startY,
            args[j],
            args[j + 1],
            x,
            y,
            x,
            y
          );
          j += 4;
          break;
        case OPS.closePath:
          ctx.closePath();
          break;
      }
    }
    current.setCurrentPoint(x, y);
  }
  closePath() {