Wordpress: Add dependency to preregistered script

functions.php

/**
 * Add dependency to a preregistered script. Returns false if script hasnt been registered.
 *
 * @param string $handle
 * @param string $dependency
 * @return bool
 */
function jl_add_script_dependency( $handle, $dependency ) {
	global $wp_scripts;

	$registered_script = $wp_scripts->query( $handle, 'registered' );
	if ( ! $registered_script )
		return false; //script isnt registered

	if ( ! in_array( $dependency, $registered_script->deps ) ) { //checks if dependency is already listed
		$script->deps[] = $dep;
	}
	return true;
}