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!
const charSpacing = current.charSpacing;
    const wordSpacing = current.wordSpacing;
    const fontDirection = current.fontDirection;
    const textHScale = current.textHScale * fontDirection;
    const glyphsLength = glyphs.length;
    const vertical = font.vertical;
    const spacingDir = vertical ? 1 : -1;
    const defaultVMetrics = font.defaultVMetrics;
    const widthAdvanceScale = fontSize * current.fontMatrix[0];
    const simpleFillText =
      current.textRenderingMode === TextRenderingMode.FILL &&
      !font.disableFontFace &&
      !current.patternFill;
    ctx.save();
    let patternTransform;
    if (current.patternFill) {
      
      
      ctx.save();
      const pattern = current.fillColor.getPattern(
        ctx,
        this,
        ctx.mozCurrentTransformInverse
      );
      patternTransform = ctx.mozCurrentTransform;
      ctx.restore();
      ctx.fillStyle = pattern;
    }
    ctx.transform.apply(ctx, current.textMatrix);
    ctx.translate(current.x, current.y + current.textRise);