它们是HTML5中的跨域属性吗？
是的，
The crossorigin attribute is a CORS settings attribute. Its purpose is to allow images from third-party sites that allow cross-origin access to be used with canvas.
您可以使用它来解决JavaScript错误，例如记录js错误：
if (securityOrigin()->canRequest(targetUrl)) {
msg = myErroe;
line = myLineNumber;
source = sourceURL;
} else {
msg = "Error!";
source = String();
line = 0;
}