WordPress File wp-includes/customize/class-wp-customize-nav-menu-locations-control.php

WP_Customize_Nav_Menu_Locations_Control

Customize Nav Menu Locations Control Class.

WP_Customize_Nav_Menu_Locations_Control::content_template()

JS/Underscore template for the control UI.

WP_Customize_Nav_Menu_Locations_Control::render_content()

Don’t render the control’s content – it uses a JS template instead.