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 drawnWidth = Math.ceil(rect[2] - rect[0]);
    const drawnHeight = Math.ceil(rect[3] - rect[1]);
    const fillCanvas = this.cachedCanvases.getCanvas(
      "fillCanvas",
      drawnWidth,
      drawnHeight,
      true
    );
    const fillCtx = fillCanvas.context;
    
    const offsetX = Math.min(cord1[0], cord2[0]);
    const offsetY = Math.min(cord1[1], cord2[1]);
    fillCtx.translate(-offsetX, -offsetY);
    fillCtx.transform.apply(fillCtx, maskToCanvas);
    
    const scaled = this._scaleImage(
      maskCanvas.canvas,
      fillCtx.mozCurrentTransformInverse
    );
    fillCtx.imageSmoothingEnabled = getImageSmoothingEnabled(
      fillCtx.mozCurrentTransform,
      img.interpolate
    );
    fillCtx.drawImage(
      scaled.img,
      0,
      0,
      scaled.img.width,
      scaled.img.height,
      0,