Attach (recommended) or Link to PDF file here: https://www.recom-power.com/pdf/Powerline-AC-DC/RAC05-K.pdf

Configuration:
- Web browser and its version: Firefox 56.0 (64-bit)
- Operating system and its version: Windows 10 with OS Build 15063.632
- PDF.js version: ?
- Is an extension: Built-in

Steps to reproduce the problem:
1. Open Page

What is the expected behavior? To properly render the first page. 
![image](https://user-images.githubusercontent.com/1151969/31415345-b1504022-add7-11e7-855b-8030a308f7a2.png)

What went wrong? Renders poorly.
![image](https://user-images.githubusercontent.com/1151969/31415363-d8842096-add7-11e7-818d-728c1102891b.png)

Link to a viewer (if hosted on a site other than mozilla.github.io/pdf.js or as Firefox/Chrome extension): ?

const paths = this.pendingTextPaths;
    const ctx = this.ctx;
    if (paths === undefined) {
      ctx.beginPath();
      return;
    }
    ctx.save();
    ctx.beginPath();
    for (let i = 0; i < paths.length; i++) {
      const path = paths[i];
      ctx.setTransform.apply(ctx, path.transform);
      ctx.translate(path.x, path.y);
      path.addToPath(ctx, path.fontSize);
    }
    ctx.restore();
    ctx.clip();
    ctx.beginPath();
    delete this.pendingTextPaths;
  }
  setCharSpacing(spacing) {
    this.current.charSpacing = spacing;
  }
  setWordSpacing(spacing) {
    this.current.wordSpacing = spacing;
  }
  setHScale(scale) {
    this.current.textHScale = scale / 100;
  }
  setLeading(leading) {