Source

File: wp-admin/includes/class-custom-image-header.php

public function __construct( $admin_header_callback, $admin_image_div_callback = '' ) {
		$this->admin_header_callback    = $admin_header_callback;
		$this->admin_image_div_callback = $admin_image_div_callback;

		add_action( 'admin_menu', array( $this, 'init' ) );

		add_action( 'customize_save_after', array( $this, 'customize_set_last_used' ) );
		add_action( 'wp_ajax_custom-header-crop', array( $this, 'ajax_header_crop' ) );
		add_action( 'wp_ajax_custom-header-add', array( $this, 'ajax_header_add' ) );
		add_action( 'wp_ajax_custom-header-remove', array( $this, 'ajax_header_remove' ) );
	}