Can't save as png in chrome.

Solution could be something like this:

function saveAsPNG() {
var oldSelectedObject = selectedObject;
selectedObject = null;
drawUsing(canvas.getContext('2d'));
selectedObject = oldSelectedObject;
var pngData = canvas.toDataURL('image/png');

var a = document.createElement('a');
a.href = pngData;
a.download = 'canvas.png';
a.click();

}