これを次から変更しました: https://medium.com/@benjamin.black/using-blob-from-svg-text-as-image-source-2a8947af7a8e
var yourSVG = document.getElementsByTagName('svg')[0];
//or use document.getElementById('yourSvgId'); etc.
yourSVG.setAttributeNS('http://www.w3.org/2000/xmlns/', 'xmlns', 'http://www.w3.org/2000/svg');
yourSVG.setAttributeNS('http://www.w3.org/2000/xmlns/', 'xmlns:xlink', 'http://www.w3.org/1999/xlink');
var serializer = new XMLSerializer();
var serialSVG = serializer.serializeToString(yourSVG);
var svg = serialSVG;
var blob = new Blob([svg], {type: 'image/svg+xml'});
var url = URL.createObjectURL(blob);
var image = document.createElement('img');
// image.addEventListener('load', () => URL.revokeObjectURL(url), {once: true});
//changed above line using babel to code below;
image.addEventListener('load', function () {
return URL.revokeObjectURL(url);
}, { once: true });
image.src = url;
//Then just use your pdf.addImage() function as usual;