Fix blocks PNG export in Webkit
@@ -181,7 +181,7 @@ goog.require('goog.Timer');
var a = document.createElement('a');
a.download = name;
- a.target = "_blank";
+ a.target = '_self';
if (canvas.toBlob === undefined) {
var src = canvas.toDataURL('image/png');
a.href = src;
