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 glyph = glyphs[i];
      if (isNum(glyph)) {
        x += (spacingDir * glyph * fontSize) / 1000;
        continue;
      }
      let restoreNeeded = false;
      const spacing = (glyph.isSpace ? wordSpacing : 0) + charSpacing;
      const character = glyph.fontChar;
      const accent = glyph.accent;
      let scaledX, scaledY;
      let width = glyph.width;
      if (vertical) {
        const vmetric = glyph.vmetric || defaultVMetrics;
        const vx =
          -(glyph.vmetric ? vmetric[1] : width * 0.5) * widthAdvanceScale;
        const vy = vmetric[2] * widthAdvanceScale;
        width = vmetric ? -vmetric[0] : width;
        scaledX = vx / fontSizeScale;
        scaledY = (x + vy) / fontSizeScale;
      } else {
        scaledX = x / fontSizeScale;
        scaledY = 0;
      }
      if (font.remeasure && width > 0) {
        
        
        
        const measuredWidth =
          ((ctx.measureText(character).width * 1000) / fontSize) *
          fontSizeScale;