shouldPreload( element ) {

		if( this.Reveal.isScrollView() ) {
			return true;
		}

		// Prefer an explicit global preload setting
		let preload = this.Reveal.getConfig().preloadIframes;

		// If no global setting is available, fall back on the element's
		// own preload setting
		if( typeof preload !== 'boolean' ) {
			preload = element.hasAttribute( 'data-preload' );
		}

		return preload;
	}
Should the given element be preloaded?
Decides based on local element attributes and global config.

@param {HTMLElement} element