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!
if (!url) {
    return false;
  }
  switch (url.protocol) {
    case "http:":
    case "https:":
    case "ftp:":
    case "mailto:":
    case "tel:":
      return true;
    default:
      return false;
  }
}
/**
 * Attempts to create a valid absolute URL.
 *
 * @param {URL|string} url - An absolute, or relative, URL.
 * @param {URL|string} [baseUrl] - An absolute URL.
 * @param {Object} [options]
 * @returns Either a valid {URL}, or `null` otherwise.
 */
function createValidAbsoluteUrl(url, baseUrl = null, options = null) {