function getContentRect(target) {
        if (!isBrowser) {
            return emptyRect;
        }
        if (isSVGGraphicsElement(target)) {
            return getSVGContentRect(target);
        }
        return getHTMLElementContentRect(target);
    }
Calculates an appropriate content rectangle for provided html or svg element.

@param {Element} target - Element content rectangle of which needs to be calculated.
@returns {DOMRectInit}