Remove [TreatNullAs=NullString] from Document.domain

Source/core/dom/Document.idl

Index: Source/core/dom/Document.idl
diff --git a/Source/core/dom/Document.idl b/Source/core/dom/Document.idl
index 9efcd84b9a382f29a48fae4cf0994798d21b0d1a..40d56b5d9697e662594d1a443f4aa6f22bc72bbf 100644
--- a/Source/core/dom/Document.idl
+++ b/Source/core/dom/Document.idl
@@ -82,8 +82,7 @@ interface Document : Node {
 
     // resource metadata management
     [PutForwards=href, Unforgeable] readonly attribute Location? location;
-    // FIXME: domain should not have [TreatNullAs=NullString].
-    [TreatNullAs=NullString, RaisesException=Setter] attribute DOMString domain;
+    [RaisesException=Setter] attribute DOMString domain;
     readonly attribute DOMString referrer;
     // FIXME: cookie should not have [TreatNullAs=NullString].
     [TreatNullAs=NullString, RaisesException] attribute DOMString cookie;