Attach (recommended) or Link to PDF file here:
[Test file.pdf](https://github.com/mozilla/pdf.js/files/4656226/Test.file.pdf)

Configuration:
- Web browser and its version: Chrome Version 81.0.4044.138 (Official Build) (64-bit)
- Operating system and its version: Windows 10
- PDF.js version: latest
- Is a browser extension: no

Steps to reproduce the problem:
1. Open [https://mozilla.github.io/pdf.js/web/viewer.html](https://mozilla.github.io/pdf.js/web/viewer.html)
2. Load the provided .pdf file

What is the expected behavior? (add screenshot)
![image](https://user-images.githubusercontent.com/5569382/82438616-02c3fe80-9aa2-11ea-9003-b75ea1e7aac6.png)

What went wrong? (add screenshot)
![image](https://user-images.githubusercontent.com/5569382/82438640-09527600-9aa2-11ea-810b-071da7e37896.png)


} else {
           M
          this._cachedGetSinglePixelWidth = 1;
        }
      }
      return this._cachedGetSinglePixelWidth;
    },
    getCanvasPosition: function CanvasGraphics_getCanvasPosition(x, y) {
      const transform = this.ctx.mozCurrentTransform;
      return [
        transform[0] * x + transform[2] * y + transform[4],
        transform[1] * x + transform[3] * y + transform[5],
      ];
    },
    isContentVisible: function CanvasGraphics_isContentVisible() {
      for (let i = this.markedContentStack.length - 1; i >= 0; i--) {
        if (!this.markedContentStack[i].visible) {
          return false;
        }
      }
      return true;
    },
  };
  for (const op in OPS) {
    CanvasGraphics.prototype[OPS[op]] = CanvasGraphics.prototype[op];
  }
  return CanvasGraphics;
})();
export { CanvasGraphics };