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)


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) {
        const transparentCanvas = this.cachedCanvases.getCanvas(
          "transparent",
          width,
          height,
          true
        );
        this.compositeCtx = this.ctx;
        this.transparentCanvas = transparentCanvas.canvas;
        this.ctx = transparentCanvas.context;
        this.ctx.save();
        
        
        this.ctx.transform.apply(