1 files changed, 27 insertions, 22 deletions

diff --git a/src/components/script/dom/domimplementation.rs b/src/components/script/dom/domimplementation.rs
index 91d2fa324d4..89e4cc95760 100644
--- a/src/components/script/dom/domimplementation.rs
+++ b/src/components/script/dom/domimplementation.rs
@@ -4,7 +4,7 @@
 
 use dom::bindings::codegen::BindingDeclarations::DOMImplementationBinding;
 use dom::bindings::codegen::InheritTypes::NodeCast;
-use dom::bindings::js::{JS, JSRef, Temporary, OptionalRootable};
+use dom::bindings::js::{JS, JSRef, Root, Temporary, OptionalRootable};
 use dom::bindings::utils::{Reflector, Reflectable, reflect_dom_object};
 use dom::bindings::error::{Fallible, InvalidCharacter, NamespaceError};
 use dom::bindings::utils::{QName, Name, InvalidXMLName, xml_name_type};
@@ -76,7 +76,7 @@ impl<'a> DOMImplementationMethods for JSRef<'a, DOMImplementation> {
 
     // http://dom.spec.whatwg.org/#dom-domimplementation-createdocument
     fn CreateDocument(&self, namespace: Option<DOMString>, qname: DOMString,
-                      mut maybe_doctype: Option<JSRef<DocumentType>>) -> Fallible<Temporary<Document>> {
+                      maybe_doctype: Option<JSRef<DocumentType>>) -> Fallible<Temporary<Document>> {
         let win = self.owner.root();
 
         // Step 1.
@@ -92,21 +92,22 @@ impl<'a> DOMImplementationMethods for JSRef<'a, DOMImplementation> {
         };
 
         {
-            let doc_node: &mut JSRef<Node> = NodeCast::from_mut_ref(&mut *doc);
+            let doc_node: &JSRef<Node> = NodeCast::from_ref(&*doc);
 
             // Step 4.
             match maybe_doctype {
                 None => (),
-                Some(ref mut doctype) => {
-                    assert!(doc_node.AppendChild(NodeCast::from_mut_ref(doctype)).is_ok())
+                Some(ref doctype) => {
+                    let doc_type: &JSRef<Node> = NodeCast::from_ref(doctype);
+                    assert!(doc_node.AppendChild(doc_type).is_ok())
                 }
             }
 
             // Step 5.
             match maybe_elem.root() {
                 None => (),
-                Some(mut elem) => {
-                    assert!(doc_node.AppendChild(NodeCast::from_mut_ref(&mut *elem)).is_ok())
+                Some(elem) => {
+                    assert!(doc_node.AppendChild(NodeCast::from_ref(&*elem)).is_ok())
                 }
             }
         }
@@ -123,44 +124,48 @@ impl<'a> DOMImplementationMethods for JSRef<'a, DOMImplementation> {
         let owner = self.owner.root();
 
         // Step 1-2.
-        let mut doc = Document::new(&owner.root_ref(), None, HTMLDocument, None).root();
-        let mut doc_alias = doc.clone();
-        let doc_node: &mut JSRef<Node> = NodeCast::from_mut_ref(&mut doc_alias);
+        let doc = Document::new(&owner.root_ref(), None, HTMLDocument, None).root();
+        let doc_node: &JSRef<Node> = NodeCast::from_ref(&*doc);
 
         {
             // Step 3.
-            let mut doc_type = DocumentType::new("html".to_owned(), None, None, &*doc).root();
-            assert!(doc_node.AppendChild(NodeCast::from_mut_ref(&mut *doc_type)).is_ok());
+            let doc_type = DocumentType::new("html".to_owned(), None, None, &*doc).root();
+            assert!(doc_node.AppendChild(NodeCast::from_ref(&*doc_type)).is_ok());
         }
 
         {
             // Step 4.
-            let mut doc_html = NodeCast::from_temporary(HTMLHtmlElement::new("html".to_owned(), &*doc)).root();
-            assert!(doc_node.AppendChild(&mut *doc_html).is_ok());
+            let doc_html: Root<Node> = NodeCast::from_temporary(HTMLHtmlElement::new("html".to_owned(), &*doc)).root();
+            let doc_html = doc_html.deref();
+            assert!(doc_node.AppendChild(doc_html).is_ok());
 
             {
                 // Step 5.
-                let mut doc_head = NodeCast::from_temporary(HTMLHeadElement::new("head".to_owned(), &*doc)).root();
-                assert!(doc_html.AppendChild(&mut *doc_head).is_ok());
+                let doc_head: Root<Node> = NodeCast::from_temporary(HTMLHeadElement::new("head".to_owned(), &*doc)).root();
+                let doc_head = doc_head.deref();
+                assert!(doc_html.AppendChild(doc_head).is_ok());
 
                 // Step 6.
                 match title {
                     None => (),
                     Some(title_str) => {
                         // Step 6.1.
-                        let mut doc_title = NodeCast::from_temporary(HTMLTitleElement::new("title".to_owned(), &*doc)).root();
-                        assert!(doc_head.AppendChild(&mut *doc_title).is_ok());
+                        let doc_title: Root<Node> = NodeCast::from_temporary(HTMLTitleElement::new("title".to_owned(), &*doc)).root();
+                        let doc_title = doc_title.deref();
+                        assert!(doc_head.AppendChild(doc_title).is_ok());
 
                         // Step 6.2.
-                        let mut title_text = Text::new(title_str, &*doc).root();
-                        assert!(doc_title.AppendChild(NodeCast::from_mut_ref(&mut *title_text)).is_ok());
+                        let title_text: Root<Text> = Text::new(title_str, &*doc).root();
+                        let title_text = title_text.deref();
+                        assert!(doc_title.AppendChild(NodeCast::from_ref(title_text)).is_ok());
                     }
                 }
             }
 
             // Step 7.
-            let mut doc_body = HTMLBodyElement::new("body".to_owned(), &*doc).root();
-            assert!(doc_html.AppendChild(NodeCast::from_mut_ref(&mut *doc_body)).is_ok());
+            let doc_body: Root<HTMLBodyElement> = HTMLBodyElement::new("body".to_owned(), &*doc).root();
+            let doc_body = doc_body.deref();
+            assert!(doc_html.AppendChild(NodeCast::from_ref(doc_body)).is_ok());
         }
 
         // Step 8.