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.markedContentStack = [];
    this.optionalContentConfig = optionalContentConfig;
    this.cachedCanvases = new CachedCanvases(this.canvasFactory);
    this.cachedCanvasPatterns = new LRUCache(MAX_CACHED_CANVAS_PATTERNS);
    this.cachedPatterns = new Map();
    if (canvasCtx) {
      
      
      addContextCurrentTransform(canvasCtx);
    }
    this._cachedGetSinglePixelWidth = null;
  }
  beginDrawing({
    transform,
    viewport,
    transparency = false,
    background = null,
  }) {
    
    
    
    
    
    const width = this.ctx.canvas.width;
    const height = this.ctx.canvas.height;
    this.ctx.save();
    this.ctx.fillStyle = background || "rgb(255, 255, 255)";
    this.ctx.fillRect(0, 0, width, height);
    this.ctx.restore();
    if (transparency) {