Source

File: wp-admin/includes/class-theme-upgrader.php

public function theme_info( $theme = null ) {
		if ( empty( $theme ) ) {
			if ( ! empty( $this->result['destination_name'] ) ) {
				$theme = $this->result['destination_name'];
			} else {
				return false;
			}
		}

		$theme = wp_get_theme( $theme );
		$theme->cache_delete();

		return $theme;
	}