Link to PDF file (or attach file here):
[pages4.pdf](https://github.com/mozilla/pdf.js/files/1128300/pages4.pdf)

Configuration:
- Web browser and its version: Firefox 54
- Operating system and its version: Win 10
- PDF.js version: 1.8.522
- Is an extension: no

What is the expected behavior? (add screenshot)
![chrome1-1 1](https://user-images.githubusercontent.com/146436/27918380-2f74512a-6245-11e7-8525-d0038fa6c2e8.jpg)
![chrome1-2 1](https://user-images.githubusercontent.com/146436/27918425-54f8e47e-6245-11e7-9bff-127f79ad0511.jpg)


What went wrong? (add screenshot)
![screenshot from 2017-07-06 12-10-30](https://user-images.githubusercontent.com/146436/27918442-5d57624e-6245-11e7-9436-5ba31cc8bd1a.png)
![screenshot from 2017-07-06 12-10-44](https://user-images.githubusercontent.com/146436/27918454-63b486da-6245-11e7-9eb5-c03aa5c40943.png)



this.markedContentStack = [];
    this.optionalContentConfig = optionalContentConfig;
    this.cachedCanvases = new CachedCanvases(this.canvasFactory);
    this.cachedCanvasPatterns = new LRUCache(MAX_CACHED_CANVAS_PATTERNS);
    this.cachedPatterns = new Map();
    if (canvasCtx) {
      
      
      addContextCurrentTransform(canvasCtx);
    }
    this._cachedGetSinglePixelWidth = null;
  }
  beginDrawing({
    transform,
    viewport,
    transparency = false,
    background = null,
  }) {
    
    
    
    
    
    const width = this.ctx.canvas.width;
    const height = this.ctx.canvas.height;
    this.ctx.save();
    this.ctx.fillStyle = background || "rgb(255, 255, 255)";
    this.ctx.fillRect(0, 0, width, height);
    this.ctx.restore();
    if (transparency) {