Add the `[social_icon]` shortcode functionality for the top bar. Usage would be something like: [social_icon url="http://facebook.com/nicethemes" icon="fa-facebook"]

smart-top-bar-social-icon.php

<?php
//* Do NOT include the opening php tag

if ( ! function_exists( 'nice_top_bar_social_icon_shortcodes' ) ) :
add_filter( 'nice_top_bar_shortcodes', 'nice_top_bar_social_icon_shortcodes' );
/**
 * Add shortcodes to top bar.
 *
 * @since  1.0.2
 *
 * @param  array $shortcodes
 *
 * @return array
 */
function nice_top_bar_social_icon_shortcodes( array $shortcodes = array() ) {
	$shortcodes['social_icon'] = 'nice_top_bar_social_icon_shortcode';

	return $shortcodes;
}
endif;

 if ( ! function_exists( 'nice_top_bar_social_icon_shortcode' ) ) :
/**
 * Process social_icon shortcode.
 *
 * @since 1.0.2
 *
 * @param array $atts
 *
 * @return string
 */
function nice_top_bar_social_icon_shortcode( array $atts = array() ) {
	$content = '';

		$icon_class = empty( $atts['icon'] ) ? '' : $atts['icon'];
		$url         = empty( $atts['url'] ) ? '' : $atts['url'];

		ob_start();
		?>
			<div class="social-icon">
				<?php if ( ! empty( $url ) ) : ?>
				<a href="<?php echo esc_url( $url ); ?>">
				<?php endif; ?>
					<?php if ( isset( $atts['icon'] ) && nice_bool( $atts['icon'] ) ) : ?>
						<i class="fa <?php echo esc_attr( $icon_class ); ?>"></i>
					<?php endif; ?>
				<?php if ( ! empty( $url ) ) : ?>
				</a>
				<?php endif; ?>
			</div>
		<?php

		$content = ob_get_contents();
		ob_end_clean();

	return $content;
}
endif;