Steps to reproduce (this PDF):
[page4.pdf](https://github.com/mozilla/pdf.js/files/5990272/page4.pdf)

````
npm install
node_modules/.bin/gulp dist-install
node examples/node/pdf2svg.js /tmp/page4.pdf
````

Error:
````
Error: Invalid SVG dimensions
    at unreachable (/tmp/pdf.js/build/dist/legacy/build/pdf.js:2086:9)
    at assert (/tmp/pdf.js/build/dist/legacy/build/pdf.js:2091:5)
    at DOMSVGFactory.create (/tmp/pdf.js/build/dist/legacy/build/pdf.js:640:24)
    at SVGGraphics._makeTilingPattern (/tmp/pdf.js/build/dist/legacy/build/pdf.js:24178:36)
    at SVGGraphics._makeColorN_Pattern (/tmp/pdf.js/build/dist/legacy/build/pdf.js:24127:23)
    at SVGGraphics.setFillColorN (/tmp/pdf.js/build/dist/legacy/build/pdf.js:24088:39)
    at SVGGraphics.executeOpTree (/tmp/pdf.js/build/dist/legacy/build/pdf.js:23634:22)
    at /tmp/pdf.js/build/dist/legacy/build/pdf.js:23508:18
    at process._tickCallback (internal/process/next_tick.js:68:7)
    at Function.Module.runMain (internal/modules/cjs/loader.js:834:11)
````
this.svgFactory = new DOMSVGFactory();
      this.current = new SVGExtraState();
      this.transformMatrix = IDENTITY_MATRIX; 
      this.transformStack = [];
      this.extraStack = [];
      this.commonObjs = commonObjs;
      this.objs = objs;
      this.pendingClip = null;
      this.pendingEOFill = false;
      this.embedFonts = false;
      this.embeddedFonts = Object.create(null);
      this.cssStyle = null;
      this.forceDataSchema = !!forceDataSchema;
      
      
      
      this._operatorIdMapping = [];
      for (const op in OPS) {
        this._operatorIdMapping[OPS[op]] = op;
      }
    }
    save() {