code: function computePixelPositionAndBoxSizingReliable() {
  		// Support: Firefox, Android 2.3 (Prefixed box-sizing versions).
  		div.style.cssText = "-webkit-box-sizing:border-box;-moz-box-sizing:border-box;" +
  			"box-sizing:border-box;padding:1px;border:1px;display:block;width:4px;margin-top:1%;" +
  			"position:absolute;top:1%";
  		docElem.appendChild( container );
  
  		var divStyle = window.getComputedStyle( div, null );
  		pixelPositionVal = divStyle.top !== "1%";
  		boxSizingReliableVal = divStyle.width === "4px";
  
  		docElem.removeChild( container );
  	}
docs: Executing both pixelPosition & boxSizingReliable tests require only one layout so they're executed at the same time to save the second computation.