Attach (recommended) or Link to PDF file here:
[shading_pattern.pdf](https://github.com/mozilla/pdf.js/files/1532598/shading_pattern.pdf)

Configuration:
- Web browser and its version: Firefox 57.0
- Operating system and its version: Debian GNU/Linux 9 64-bit
- PDF.js version: tried with Firefox's 1.9.583 and with online viewer 2.0.185
- Is a browser extension: no

Steps to reproduce the problem:
1. Open the attached file with the online viewer https://mozilla.github.io/pdf.js/web/viewer.html

What is the expected behavior? (add screenshot)
![image](https://user-images.githubusercontent.com/11061462/33626267-d9a57dee-d9d8-11e7-8712-cfa17c038259.png)
(Image captured from Adobe Reader CS.) The shading needs to be inside the letters.

What went wrong? (add screenshot)
![image](https://user-images.githubusercontent.com/11061462/33626285-eaabd462-d9d8-11e7-94e2-96480b57750d.png)
The shading seems to be displaced and upside-down, for it does not cover all the characters of the word.

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

}
      ctx.putImageData(chunkImgData, 0, i * FULL_CHUNK_HEIGHT);
    }
  } else if (imgData.kind === ImageKind.RGBA_32BPP) {
    
    const hasTransferMaps = !!(
      transferMapRed ||
      transferMapGreen ||
      transferMapBlue
    );
    j = 0;
    elemsInThisChunk = width * FULL_CHUNK_HEIGHT * 4;
    for (i = 0; i < fullChunks; i++) {
      dest.set(src.subarray(srcPos, srcPos + elemsInThisChunk));
      srcPos += elemsInThisChunk;
      if (hasTransferMaps) {
        for (let k = 0; k < elemsInThisChunk; k += 4) {
          if (transferMapRed) {
            dest[k + 0] = transferMapRed[dest[k + 0]];
          }
          if (transferMapGreen) {
            dest[k + 1] = transferMapGreen[dest[k + 1]];
          }
          if (transferMapBlue) {
            dest[k + 2] = transferMapBlue[dest[k + 2]];
          }
        }
      }
      ctx.putImageData(chunkImgData, 0, j);
      j += FULL_CHUNK_HEIGHT;