Build the HTML representation for the mapviz.

def as_iframe(self, html_data):
        """Build the HTML representation for the mapviz."""

        srcdoc = html_data.replace('"', "'")
        return ('<iframe id="{div_id}", srcdoc="{srcdoc}" style="width: {width}; '
                'height: {height};"></iframe>'.format(
                    div_id=self.div_id,
                    srcdoc=srcdoc,
                    width=self.width,
                    height=self.height))