fixup! Add DOMException cause

Author: legendecas

index.bs

@@ -14562,13 +14562,13 @@ fragment:
 
 dictionary DOMExceptionOptions {
   any cause;
-  DOMString name;
+  DOMString name = "Error";
 };
 
 [Exposed=(Window,Worker),
  Serializable]
 interface DOMException { // but see below note about ECMAScript binding
-  constructor(optional DOMString message = "", optional (DOMString or DOMExceptionOptions) nameOrOptions = "Error");
+  constructor(optional DOMString message = "", optional (DOMExceptionOptions or DOMString) options = {});
   readonly attribute DOMString name;
   readonly attribute DOMString message;
   readonly attribute unsigned short code;
@@ -14614,13 +14614,10 @@ The
 constructor steps are:
 
 1.  Set [=this=]'s [=DOMException/message=] to |message|.
-1.  If |nameOrOptions| is a String, set [=this=]'s [=DOMException/name=] to
-    |nameOrOptions|.
-1.  Else,
-    1.  If |nameOrOptions|'name is present, set [=this=]'s [=DOMException/name=]
-        to |nameOrOptions|'s name, else set [=this=]'s [=DOMException/name=]
-        to "Error".
-    1.  Perform [=?=] <a abstract-op>InstallErrorCause</a>([=this=], |nameOrOptions|).
+1.  If |options| is a string, then set [=this=]'s [=DOMException/name=] to |options|.
+1.  Otherwise,
+    1.  Set [=this=]'s [=DOMException/name=] to |options|["{{DOMExceptionOptions/name}}"].
+    1.  Perform [=?=] <a abstract-op>InstallErrorCause</a>([=this=], |options|).
 
 The <dfn attribute for="DOMException"><code>name</code></dfn> getter steps are to return
 [=this=]'s [=DOMException/name=].