PDFs from lumileds.com do not load with PDF.js. Part of the background loads, then only the spinner continues while using 100% CPU. 

An example pdf is http://www.lumileds.com/uploads/17/DS61-pdf 

This behaviour occurs with both the release version of pdf.js in firefox 41.0.2 and the latest .xpi downloaded from this github page.

while (this.stateStack.length || this.current.activeSMask !== null) {
      this.restore();
    }
    this.ctx.restore();
    if (this.transparentCanvas) {
      this.ctx = this.compositeCtx;
      this.ctx.save();
      this.ctx.setTransform(1, 0, 0, 1, 0, 0); 
      this.ctx.drawImage(this.transparentCanvas, 0, 0);
      this.ctx.restore();
      this.transparentCanvas = null;
    }
    this.cachedCanvases.clear();
    this.cachedCanvasPatterns.clear();
    this.cachedPatterns.clear();
    if (this.imageLayer) {
      this.imageLayer.endLayout();
    }
  }
  _scaleImage(img, inverseTransform) {