Custom_Image_Header::process_default_headers()

	public function process_default_headers() {
		global $_wp_default_headers;

		if ( !isset($_wp_default_headers) )
			return;

		if ( ! empty( $this->default_headers ) ) {
			return;
		}

		$this->default_headers = $_wp_default_headers;
		$template_directory_uri = get_template_directory_uri();
		$stylesheet_directory_uri = get_stylesheet_directory_uri();
		foreach ( array_keys($this->default_headers) as $header ) {
			$this->default_headers[$header]['url'] =  sprintf( $this->default_headers[$header]['url'], $template_directory_uri, $stylesheet_directory_uri );
			$this->default_headers[$header]['thumbnail_url'] =  sprintf( $this->default_headers[$header]['thumbnail_url'], $template_directory_uri, $stylesheet_directory_uri );
		}
	}