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 currentTransform = currentCtx.mozCurrentTransform;
    if (group.matrix) {
      currentCtx.transform.apply(currentCtx, group.matrix);
    }
    if (!group.bbox) {
      throw new Error("Bounding box is required.");
    }
    
    
    let bounds = Util.getAxialAlignedBoundingBox(
      group.bbox,
      currentCtx.mozCurrentTransform
    );
    
    const canvasBounds = [
      0,
      0,
      currentCtx.canvas.width,
      currentCtx.canvas.height,
    ];
    bounds = Util.intersect(bounds, canvasBounds) || [0, 0, 0, 0];
    
    
    const offsetX = Math.floor(bounds[0]);
    const offsetY = Math.floor(bounds[1]);
    let drawnWidth = Math.max(Math.ceil(bounds[2]) - offsetX, 1);
    let drawnHeight = Math.max(Math.ceil(bounds[3]) - offsetY, 1);
    let scaleX = 1,
      scaleY = 1;
    if (drawnWidth > MAX_GROUP_SIZE) {