Rearrange the XHR interfaces to match the spec order

Source/core/xmlhttprequest/XMLHttpRequestEventTarget.idl

Index: Source/core/xmlhttprequest/XMLHttpRequestEventTarget.idl
diff --git a/Source/core/xmlhttprequest/XMLHttpRequestEventTarget.idl b/Source/core/xmlhttprequest/XMLHttpRequestEventTarget.idl
index 7b5cd5d3435ae9f5eee929ccdad3f11aa4f3593e..3a16c7737310523d19a8220bf54ac8b86a6c9398 100644
--- a/Source/core/xmlhttprequest/XMLHttpRequestEventTarget.idl
+++ b/Source/core/xmlhttprequest/XMLHttpRequestEventTarget.idl
@@ -24,14 +24,17 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
+// https://xhr.spec.whatwg.org/#xmlhttprequesteventtarget
+
 [
     Exposed=(Window,DedicatedWorker,SharedWorker)
 ] interface XMLHttpRequestEventTarget : EventTarget {
+    // event handlers
+    attribute EventHandler onloadstart;
+    attribute EventHandler onprogress;
     attribute EventHandler onabort;
     attribute EventHandler onerror;
     attribute EventHandler onload;
-    attribute EventHandler onloadend;
-    attribute EventHandler onloadstart;
-    attribute EventHandler onprogress;
     attribute EventHandler ontimeout;
+    attribute EventHandler onloadend;
 };