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!
}
      tmpCanvas = this.cachedCanvases.getCanvas(
        tmpCanvasId,
        newWidth,
        newHeight
      );
      tmpCtx = tmpCanvas.context;
      tmpCtx.clearRect(0, 0, newWidth, newHeight);
      tmpCtx.drawImage(
        img,
        0,
        0,
        paintWidth,
        paintHeight,
        0,
        0,
        newWidth,
        newHeight
      );
      img = tmpCanvas.canvas;
      paintWidth = newWidth;
      paintHeight = newHeight;
      tmpCanvasId = tmpCanvasId === "prescale1" ? "prescale2" : "prescale1";
    }
    return {
      img,
      paintWidth,
      paintHeight,
    };
  }