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!
this.current.leading = -leading;
  }
  setFont(fontRefName, size) {
    const fontObj = this.commonObjs.get(fontRefName);
    const current = this.current;
    if (!fontObj) {
      throw new Error(`Can't find font for ${fontRefName}`);
    }
    current.fontMatrix = fontObj.fontMatrix || FONT_IDENTITY_MATRIX;
    
    
    if (current.fontMatrix[0] === 0 || current.fontMatrix[3] === 0) {
      warn("Invalid font matrix for font " + fontRefName);
    }
    
    
    if (size < 0) {
      size = -size;
      current.fontDirection = -1;
    } else {
      current.fontDirection = 1;
    }
    this.current.font = fontObj;
    this.current.fontSize = size;
    if (fontObj.isType3Font) {
      return; 
    }
    const name = fontObj.loadedName || "sans-serif";
    let bold = "normal";
    if (fontObj.black) {