Link to PDF file (or attach file here):
[RP_25884_V2_UEL Semi Finals 2016-17_concepts.pdf](https://github.com/mozilla/pdf.js/files/994423/RP_25884_V2_UEL.Semi.Finals.2016-17_concepts.pdf)

Configuration:
- Web browser and its version: Chrome 58, Firefox 53
- Operating system and its version: MacOS 10.11.6
- PDF.js version:
- Is an extension: No

Steps to reproduce the problem:
1.  View the file the file


What is the expected behavior? (add screenshot)
<img width="560" alt="screen shot 2017-05-11 at 2 06 36 pm" src="https://cloud.githubusercontent.com/assets/2474027/25971992/189f4ebe-3653-11e7-8847-c9011984cb8d.png">

What went wrong? (add screenshot)
Textlayer exists here but font fails to render. No warning in the console from what I can see. Maybe related to the gradient?

<img width="637" alt="screen shot 2017-05-11 at 2 06 20 pm" src="https://cloud.githubusercontent.com/assets/2474027/25971997/1b518cc6-3653-11e7-96c0-9a03ffcb7d6e.png">

Thanks!
scaleY,
        positions[i],
        positions[i + 1],
      ]);
      const [x, y] = Util.applyTransform([0, 0], trans);
      ctx.drawImage(mask.canvas, x, y);
    }
    ctx.restore();
  }
  paintImageMaskXObjectGroup(images) {
    if (!this.contentVisible) {
      return;
    }
    const ctx = this.ctx;
    const fillColor = this.current.fillColor;
    const isPatternFill = this.current.patternFill;
    for (let i = 0, ii = images.length; i < ii; i++) {
      const image = images[i];
      const width = image.width,
        height = image.height;
      const maskCanvas = this.cachedCanvases.getCanvas(
        "maskCanvas",
        width,
        height
      );
      const maskCtx = maskCanvas.context;
      maskCtx.save();
      putBinaryImageMask(maskCtx, image);
      maskCtx.globalCompositeOperation = "source-in";
      maskCtx.fillStyle = isPatternFill