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.

const groupCtx = this.ctx;
    this.groupLevel--;
    this.ctx = this.groupStack.pop();
    composeSMask(this.ctx, this.current.activeSMask, groupCtx);
    this.ctx.restore();
    copyCtxState(groupCtx, this.ctx);
    
    
    const deltaTransform = Util.transform(
      this.current.activeSMask.startTransformInverse,
      groupCtx.mozCurrentTransform
    );
    this.ctx.transform.apply(this.ctx, deltaTransform);
  }
  save() {
    this.ctx.save();
    const old = this.current;
    this.stateStack.push(old);
    this.current = old.clone();
    this.current.resumeSMaskCtx = null;
  }
  restore() {