Is there a way to save the SVG generated by raphael as an svg file. Note it only need to work in chrome.
As stef commented, the BlobBuilder API is deprecated. Instead, use the Blob API.
Building on Andreas' answer, here is how I quickly got it to work:
svgString = r.toSVG();
a = document.createElement('a');
a.download = 'mySvg.svg';
a.type = 'image/svg+xml';
blob = new Blob([svgString], {"type": "image/svg+xml"});
a.href = (window.URL || webkitURL).createObjectURL(blob);
a.click();