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): ?

for (j = 0; j < thisChunkHeight; j++) {
        const srcDiff = srcLength - srcPos;
        let k = 0;
        const kEnd = srcDiff > fullSrcDiff ? width : srcDiff * 8 - 7;
        const kEndUnrolled = kEnd & ~7;
        let mask = 0;
        let srcByte = 0;
        for (; k < kEndUnrolled; k += 8) {
          srcByte = src[srcPos++];
          dest32[destPos++] = srcByte & 128 ? white : black;
          dest32[destPos++] = srcByte & 64 ? white : black;
          dest32[destPos++] = srcByte & 32 ? white : black;
          dest32[destPos++] = srcByte & 16 ? white : black;
          dest32[destPos++] = srcByte & 8 ? white : black;
          dest32[destPos++] = srcByte & 4 ? white : black;
          dest32[destPos++] = srcByte & 2 ? white : black;
          dest32[destPos++] = srcByte & 1 ? white : black;
        }
        for (; k < kEnd; k++) {
          if (mask === 0) {
            srcByte = src[srcPos++];
            mask = 128;
          }
          dest32[destPos++] = srcByte & mask ? white : black;
          mask >>= 1;
        }
      }
      
      while (destPos < dest32DataLength) {
        dest32[destPos++] = 0;