get_theme_feature_list( bool $api = true )

function get_theme_feature_list( $api = true ) {
	// Hard-coded list is used if api not accessible.
	$features = array(

		__( 'Subject' )  => array(
			'blog'           => __( 'Blog' ),
			'e-commerce'     => __( 'E-Commerce' ),
			'education'      => __( 'Education' ),
			'entertainment'  => __( 'Entertainment' ),
			'food-and-drink' => __( 'Food & Drink' ),
			'holiday'        => __( 'Holiday' ),
			'news'           => __( 'News' ),
			'photography'    => __( 'Photography' ),
			'portfolio'      => __( 'Portfolio' ),
		),

		__( 'Features' ) => array(
			'accessibility-ready'   => __( 'Accessibility Ready' ),
			'custom-background'     => __( 'Custom Background' ),
			'custom-colors'         => __( 'Custom Colors' ),
			'custom-header'         => __( 'Custom Header' ),
			'custom-logo'           => __( 'Custom Logo' ),
			'editor-style'          => __( 'Editor Style' ),
			'featured-image-header' => __( 'Featured Image Header' ),
			'featured-images'       => __( 'Featured Images' ),
			'footer-widgets'        => __( 'Footer Widgets' ),
			'full-width-template'   => __( 'Full Width Template' ),
			'post-formats'          => __( 'Post Formats' ),
			'sticky-post'           => __( 'Sticky Post' ),
			'theme-options'         => __( 'Theme Options' ),
		),

		__( 'Layout' ) => array(
			'grid-layout'   => __( 'Grid Layout' ),
			'one-column'    => __( 'One Column' ),
			'two-columns'   => __( 'Two Columns' ),
			'three-columns' => __( 'Three Columns' ),
			'four-columns'  => __( 'Four Columns' ),
			'left-sidebar'  => __( 'Left Sidebar' ),
			'right-sidebar' => __( 'Right Sidebar' ),
		)

	);

	if ( ! $api || ! current_user_can( 'install_themes' ) )
		return $features;

	if ( !$feature_list = get_site_transient( 'wporg_theme_feature_list' ) )
		set_site_transient( 'wporg_theme_feature_list', array(), 3 * HOUR_IN_SECONDS );

	if ( !$feature_list ) {
		$feature_list = themes_api( 'feature_list', array() );
		if ( is_wp_error( $feature_list ) )
			return $features;
	}

	if ( !$feature_list )
		return $features;

	set_site_transient( 'wporg_theme_feature_list', $feature_list, 3 * HOUR_IN_SECONDS );

	$category_translations = array(
		'Layout'   => __( 'Layout' ),
		'Features' => __( 'Features' ),
		'Subject'  => __( 'Subject' ),
	);

	// Loop over the wporg canonical list and apply translations
	$wporg_features = array();
	foreach ( (array) $feature_list as $feature_category => $feature_items ) {
		if ( isset($category_translations[$feature_category]) )
			$feature_category = $category_translations[$feature_category];
		$wporg_features[$feature_category] = array();

		foreach ( $feature_items as $feature ) {
			if ( isset($features[$feature_category][$feature]) )
				$wporg_features[$feature_category][$feature] = $features[$feature_category][$feature];
			else
				$wporg_features[$feature_category][$feature] = $feature;
		}
	}

	return $wporg_features;
}