spec/helpers/dom-utils.js
function forceReflow ( element ) {
    if ( !varExists( $ ) ) throw new Error( "This method uses jQuery, but the $ variable is not available" );

    var $element =  element instanceof $ ? element : $( element );

    $element.css( { display: "none" } ).height();
    $element.css( { display: "block" } );
}
function forceReflow ( element ) {
    if ( !varExists( $ ) ) throw new Error( "This method uses jQuery, but the $ variable is not available" );

    var $element =  element instanceof $ ? element : $( element );

    $element.css( { display: "none" } ).height();
    $element.css( { display: "block" } );
}
function forceReflow ( element ) { if ( ! varExists ( $ ) ) throw new Error ( "This method uses jQuery, but the $ variable is not available" ) ; var $element = element instanceof $ ? element : $ ( element ) ; $element . css ( { display : "none" } ) . height ( ) ; $element . css ( { display : "block" } ) ; }
Forces a reflow for a given element, in case it doesn't happen automatically.

For the technique, see http://stackoverflow.com/a/14382251/508355

For some background, see e.g. http://apmblog.dynatrace.com/2009/12/12/understanding-internet-explorer-rendering-behaviour/

@param {HTMLElement|jQuery} element
Forces a reflow for a given element in case it doesn t happen automatically .