Remove needless mutabilities from script crate.

src/components/script/dom/document.rs

@@ -186,7 +186,7 @@ impl<'a> DocumentHelpers for JSRef<'a, Document> {
     }
 
     fn load_anchor_href(&self, href: DOMString) {
-        let mut window = self.window.root();
+        let window = self.window.root();
         window.load_url(href);
     }
 }
@@ -197,7 +197,7 @@ impl Document {
                             wrap_fn: extern "Rust" fn(*mut JSContext, &JSRef<Window>, Box<Document>) -> JS<Document>)
              -> Temporary<Document> {
         assert!(document.reflector().get_jsobject().is_null());
-        let mut raw_doc = reflect_dom_object(document, window, wrap_fn).root();
+        let raw_doc = reflect_dom_object(document, window, wrap_fn).root();
         assert!(raw_doc.reflector().get_jsobject().is_not_null());
 
         let doc_alias = raw_doc.clone();
@@ -693,7 +693,7 @@ impl<'a> DocumentMethods for JSRef<'a, Document> {
             }
 
             let element: &JSRef<Element> = ElementCast::to_ref(node).unwrap();
-            element.get_attribute(Null, "name").root().map_or(false, |mut attr| {
+            element.get_attribute(Null, "name").root().map_or(false, |attr| {
                 attr.value().as_slice() == name.as_slice()
             })
         })
@@ -804,7 +804,7 @@ impl<'a> DocumentMethods for JSRef<'a, Document> {
     }
 
     fn Location(&self) -> Temporary<Location> {
-        let mut window = self.window.root();
+        let window = self.window.root();
         window.Location()
     }
 

src/components/script/dom/domimplementation.rs

@@ -76,7 +76,7 @@ impl<'a> DOMImplementationMethods for JSRef<'a, DOMImplementation> {
         let win = self.owner.root();
 
         // Step 1.
-        let mut doc = Document::new(&win.root_ref(), None, NonHTMLDocument, None).root();
+        let doc = Document::new(&win.root_ref(), None, NonHTMLDocument, None).root();
         // Step 2-3.
         let maybe_elem = if qname.is_empty() {
             None

src/components/script/dom/element.rs

@@ -794,7 +794,7 @@ impl<'a> VirtualMethods for JSRef<'a, Element> {
             "id" => {
                 let node: &JSRef<Node> = NodeCast::from_ref(self);
                 if node.is_in_doc() {
-                    let mut doc = document_from_node(self).root();
+                    let doc = document_from_node(self).root();
                     doc.register_named_element(self, value.clone());
                 }
             }
@@ -817,7 +817,7 @@ impl<'a> VirtualMethods for JSRef<'a, Element> {
             "id" => {
                 let node: &JSRef<Node> = NodeCast::from_ref(self);
                 if node.is_in_doc() {
-                    let mut doc = document_from_node(self).root();
+                    let doc = document_from_node(self).root();
                     doc.unregister_named_element(self, value);
                 }
             }

src/components/script/dom/htmlanchorelement.rs

@@ -58,7 +58,7 @@ impl<'a> PrivateHTMLAnchorElementHelpers for JSRef<'a, HTMLAnchorElement> {
                     let value = href.Value();
                     debug!("clicked on link to {:s}", value);
                     let node: &JSRef<Node> = NodeCast::from_ref(self);
-                    let mut doc = node.owner_doc().root();
+                    let doc = node.owner_doc().root();
                     doc.load_anchor_href(value);
                 }
                 None => ()

src/components/script/dom/htmlbodyelement.rs

@@ -76,7 +76,7 @@ impl<'a> VirtualMethods for JSRef<'a, HTMLBodyElement> {
                   "onbeforeunload", "onhashchange", "onlanguagechange", "onmessage",
                   "onoffline", "ononline", "onpagehide", "onpageshow", "onpopstate",
                   "onstorage", "onresize", "onunload", "onerror"];
-            let mut window = window_from_node(self).root();
+            let window = window_from_node(self).root();
             let (cx, url, reflector) = (window.get_cx(),
                                         window.get_url(),
                                         window.reflector().get_jsobject());

src/components/script/dom/htmlelement.rs

@@ -105,7 +105,7 @@ impl<'a> VirtualMethods for JSRef<'a, HTMLElement> {
         }
 
         if name.as_slice().starts_with("on") {
-            let mut window = window_from_node(self).root();
+            let window = window_from_node(self).root();
             let (cx, url, reflector) = (window.get_cx(),
                                         window.get_url(),
                                         window.reflector().get_jsobject());

src/components/script/dom/node.rs

@@ -1137,7 +1137,7 @@ impl Node {
         for node in nodes.mut_iter() {
             parent.add_child(node, child);
             let is_in_doc = parent.is_in_doc();
-            for mut kid in node.traverse_preorder() {
+            for kid in node.traverse_preorder() {
                 if is_in_doc {
                     kid.flags.deref().borrow_mut().insert(IsInDoc);
                 } else {
@@ -1248,7 +1248,7 @@ impl Node {
 
         // Step 2.
         // XXXabinader: clone() for each node as trait?
-        let mut copy: Root<Node> = match node.type_id() {
+        let copy: Root<Node> = match node.type_id() {
             DoctypeNodeTypeId => {
                 let doctype: &JSRef<DocumentType> = DocumentTypeCast::to_ref(node).unwrap();
                 let doctype = doctype.deref();

src/components/script/html/hubbub_html_parser.rs

@@ -379,7 +379,7 @@ pub fn parse_html(page: &Page,
                 SvgNs => namespace::SVG,
                 ns => fail!("Not expecting namespace {:?}", ns),
             };
-            let mut element: Root<Element> = build_element_from_tag(tag.name.clone(), namespace, *tmp).root();
+            let element: Root<Element> = build_element_from_tag(tag.name.clone(), namespace, *tmp).root();
 
             debug!("-- attach attrs");
             for attr in tag.attributes.iter() {

src/components/script/script_task.rs

@@ -540,11 +540,11 @@ impl ScriptTask {
         let cx = self.js_context.borrow();
         let cx = cx.get_ref();
         // Create the window and document objects.
-        let mut window = Window::new(cx.deref().ptr,
+        let window = Window::new(cx.deref().ptr,
-                                     page.clone(),
+                                 page.clone(),
-                                     self.chan.clone(),
+                                 self.chan.clone(),
-                                     self.compositor.dup(),
+                                 self.compositor.dup(),
-                                     self.image_cache_task.clone()).root();
+                                 self.image_cache_task.clone()).root();
         let document = Document::new(&*window, Some(url.clone()), HTMLDocument, None).root();
         window.deref().init_browser_context(&*document);
 
@@ -679,7 +679,7 @@ impl ScriptTask {
                 };
 
                 match window.root() {
-                    Some(mut window) => {
+                    Some(window) => {
                         // http://dev.w3.org/csswg/cssom-view/#resizing-viewports
                         // https://dvcs.w3.org/hg/dom3events/raw-file/tip/html/DOM3-Events.html#event-type-resize
                         let uievent = UIEvent::new(&window.clone(),