**Link to PDF file (or attach file here):**
[tocheckFile.pdf](https://github.com/mozilla/pdf.js/files/240714/tocheckFile.pdf)

**Configuration:**
- Web browser and its version: FF45.0.2, Chrome Version 50.0.2661.86 (64-bit) 
- Operating system and its version: Mac OSX El Capitan

**\- PDF.js version:**
PDFJS.version = '1.1.215';
PDFJS.build = 'c9a7498';

**Steps to reproduce the problem:**
1. Use the lib to generate a PDF preview.

**What is the expected behavior? (add screenshot)**
PDF preview should have rendered completely. (frog head should be complete)

**What went wrong? (add screenshot)**
<img width="952" alt="imagesnotrenderinginpreview" src="https://cloud.githubusercontent.com/assets/10231850/14889265/cecb2d64-0d66-11e6-98e1-da2d39728552.png">

See attached screenshot in regards to the pdf file

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

ctx.strokeStyle = "#000000";
  ctx.fillStyle = "#000000";
  ctx.fillRule = "nonzero";
  ctx.globalAlpha = 1;
  ctx.lineWidth = 1;
  ctx.lineCap = "butt";
  ctx.lineJoin = "miter";
  ctx.miterLimit = 10;
  ctx.globalCompositeOperation = "source-over";
  ctx.font = "10px sans-serif";
  if (ctx.setLineDash !== undefined) {
    ctx.setLineDash([]);
    ctx.lineDashOffset = 0;
  }
}
function composeSMaskBackdrop(bytes, r0, g0, b0) {