auto merge of #2063 : lpy/servo/issue2059, r=Ms2ger

see #2059

src/components/script/dom/element.rs

@@ -443,6 +443,11 @@ impl Element {
 }
 
 impl Element {
+    // http://dom.spec.whatwg.org/#dom-element-namespaceuri
+    pub fn NamespaceURI(&self) -> DOMString {
+        self.namespace.to_str().to_owned()
+    }
+
     // http://dom.spec.whatwg.org/#dom-element-tagname
     pub fn TagName(&self) -> DOMString {
         self.tag_name.to_ascii_upper()

src/components/script/dom/node.rs

@@ -1733,12 +1733,6 @@ impl Node {
         false
     }
 
-    // http://dom.spec.whatwg.org/#dom-node-namespaceuri
-    pub fn GetNamespaceURI(&self, abstract_self: &JS<Node>) -> Option<DOMString> {
-        let element: Option<JS<Element>> = ElementCast::to(abstract_self);
-        element.map(|element| element.get().namespace.to_str().to_owned())
-    }
-
     // http://dom.spec.whatwg.org/#dom-node-prefix
     pub fn GetPrefix(&self) -> Option<DOMString> {
         None

src/components/script/dom/webidls/Element.webidl

@@ -18,10 +18,11 @@ interface Element : Node {
   We haven't moved these from Node to Element like the spec wants.
 
   [Throws]
-  readonly attribute DOMString? namespaceURI;
   readonly attribute DOMString? prefix;
   readonly attribute DOMString localName;
 */
+  [Constant]
+  readonly attribute DOMString namespaceURI;
   // Not [Constant] because it depends on which document we're in
   [Pure]
   readonly attribute DOMString tagName;

src/components/script/dom/webidls/Node.webidl

@@ -79,11 +79,9 @@ interface Node : EventTarget {
 
   // Mozilla-specific stuff
   // These have been moved to Element in the spec.
-  // If we move namespaceURI, prefix and localName to Element they should return
+  // If we move prefix and localName to Element they should return
   // a non-nullable type.
   [Constant]
-  readonly attribute DOMString? namespaceURI;
-  [Constant]
   readonly attribute DOMString? prefix;
   [Constant]
   readonly attribute DOMString? localName;