bindings: Return errors in Result rather than setting an out parameter

Fixes #909.

73 files changed, 891 insertions, 550 deletions

diff --git a/src/components/script/dom/bindings/codegen/CodegenRust.py b/src/components/script/dom/bindings/codegen/CodegenRust.py
index bbd5b9b8ee6..561466f00bf 100644
--- a/src/components/script/dom/bindings/codegen/CodegenRust.py
+++ b/src/components/script/dom/bindings/codegen/CodegenRust.py
@@ -2925,8 +2925,6 @@ class CGCallGenerator(CGThing):
         # Return values that go in outparams go here
         if resultOutParam:
             args.append(CGGeneric("result"))
-        if isFallible:
-            args.append(CGGeneric("&mut rv"))
 
         needsCx = (typeNeedsCx(returnType, True) or
                    any(typeNeedsCx(a.type) for (a, _) in arguments) or
@@ -2944,21 +2942,29 @@ class CGCallGenerator(CGThing):
         else: 
             call = CGWrapper(call, pre="(*%s)." % object)
         call = CGList([call, CGWrapper(args, pre="(", post=");")])
-        if result is not None:
-            if declareResult:
-                result = CGWrapper(result, pre="let mut result: ", post=";")
-                self.cgRoot.prepend(result)
-            if not resultOutParam:
-                call = CGWrapper(call, pre="result = ")
+
+        if isFallible:
+            self.cgRoot.prepend(CGWrapper(result if result is not None else CGGeneric("()"),
+                pre="let mut result_fallible: Result<", post=",Error>;"))
+
+        if result is not None and declareResult:
+            result = CGWrapper(result, pre="let mut result: ", post=";")
+            self.cgRoot.prepend(result)
+
+        if isFallible:
+            call = CGWrapper(call, pre="result_fallible = ")
+        elif result is not None and not resultOutParam:
+            call = CGWrapper(call, pre="result = ")
 
         call = CGWrapper(call)
         self.cgRoot.append(call)
 
         if isFallible:
-            self.cgRoot.prepend(CGGeneric("let mut rv: ErrorResult = Ok(());"))
-            self.cgRoot.append(CGGeneric("if (rv.is_err()) {"))
+            self.cgRoot.append(CGGeneric("if (result_fallible.is_err()) {"))
             self.cgRoot.append(CGIndenter(errorReport))
             self.cgRoot.append(CGGeneric("}"))
+            if result is not None and not resultOutParam:
+                self.cgRoot.append(CGGeneric("result = result_fallible.unwrap();"))
 
     def define(self):
         return self.cgRoot.define()
diff --git a/src/components/script/dom/bindings/utils.rs b/src/components/script/dom/bindings/utils.rs
index f8f4448503b..6f931cc3290 100644
--- a/src/components/script/dom/bindings/utils.rs
+++ b/src/components/script/dom/bindings/utils.rs
@@ -752,7 +752,9 @@ pub enum Error {
     InvalidCharacter,
 }
 
-pub type ErrorResult = Result<(), Error>;
+pub type Fallible<T> = Result<T, Error>;
+
+pub type ErrorResult = Fallible<()>;
 
 pub struct EnumEntry {
     value: &'static str,
diff --git a/src/components/script/dom/characterdata.rs b/src/components/script/dom/characterdata.rs
index 2dbf0bdf085..283f0a74f4e 100644
--- a/src/components/script/dom/characterdata.rs
+++ b/src/components/script/dom/characterdata.rs
@@ -4,7 +4,7 @@
 
 //! DOM bindings for `CharacterData`.
 
-use dom::bindings::utils::{DOMString, ErrorResult};
+use dom::bindings::utils::{DOMString, ErrorResult, Fallible};
 use dom::bindings::utils::{BindingObject, CacheableWrapper, WrapperCache};
 use dom::node::{Node, NodeTypeId, ScriptView};
 use js::jsapi::{JSObject, JSContext};
@@ -26,31 +26,33 @@ impl CharacterData {
         Some(self.data.clone())
     }
 
-    pub fn SetData(&mut self, arg: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetData(&mut self, arg: &DOMString) -> ErrorResult {
         self.data = arg.get_ref().clone();
+        Ok(())
     }
 
     pub fn Length(&self) -> u32 {
         self.data.len() as u32
     }
 
-    pub fn SubstringData(&self, offset: u32, count: u32, _rv: &mut ErrorResult) -> DOMString {
-        Some(self.data.slice(offset as uint, count as uint).to_str())
+    pub fn SubstringData(&self, offset: u32, count: u32) -> Fallible<DOMString> {
+        Ok(Some(self.data.slice(offset as uint, count as uint).to_str()))
     }
 
-    pub fn AppendData(&mut self, arg: &DOMString, _rv: &mut ErrorResult) {
+    pub fn AppendData(&mut self, arg: &DOMString) -> ErrorResult {
         self.data.push_str(arg.get_ref().clone());
+        Ok(())
     }
 
-    pub fn InsertData(&mut self, _offset: u32, _arg: &DOMString, _rv: &mut ErrorResult) {
+    pub fn InsertData(&mut self, _offset: u32, _arg: &DOMString) -> ErrorResult {
         fail!("CharacterData::InsertData() is unimplemented")
     }
 
-    pub fn DeleteData(&mut self, _offset: u32, _count: u32, _rv: &mut ErrorResult) {
+    pub fn DeleteData(&mut self, _offset: u32, _count: u32) -> ErrorResult {
         fail!("CharacterData::DeleteData() is unimplemented")
     }
 
-    pub fn ReplaceData(&mut self, _offset: u32, _count: u32, _arg: &DOMString, _rv: &mut ErrorResult) {
+    pub fn ReplaceData(&mut self, _offset: u32, _count: u32, _arg: &DOMString) -> ErrorResult {
         fail!("CharacterData::ReplaceData() is unimplemented")
     }
 }
diff --git a/src/components/script/dom/comment.rs b/src/components/script/dom/comment.rs
index c72dc529a40..8cda0a033b4 100644
--- a/src/components/script/dom/comment.rs
+++ b/src/components/script/dom/comment.rs
@@ -2,7 +2,7 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-use dom::bindings::utils::{DOMString, ErrorResult, null_str_as_empty};
+use dom::bindings::utils::{DOMString, Fallible, null_str_as_empty};
 use dom::characterdata::CharacterData;
 use dom::node::{AbstractNode, ScriptView, CommentNodeTypeId, Node};
 use dom::window::Window;
@@ -20,11 +20,11 @@ impl Comment {
         }
     }
 
-    pub fn Constructor(owner: @mut Window, data: &DOMString, _rv: &mut ErrorResult) -> AbstractNode<ScriptView> {
+    pub fn Constructor(owner: @mut Window, data: &DOMString) -> Fallible<AbstractNode<ScriptView>> {
         let s = null_str_as_empty(data);
         unsafe {
             let compartment = (*owner.page).js_info.get_ref().js_compartment;
-            Node::as_abstract_node(compartment.cx.ptr, @Comment::new(s))
+            Ok(Node::as_abstract_node(compartment.cx.ptr, @Comment::new(s)))
         }
     }
 }
diff --git a/src/components/script/dom/document.rs b/src/components/script/dom/document.rs
index b0f86bd04ef..5ad111c0515 100644
--- a/src/components/script/dom/document.rs
+++ b/src/components/script/dom/document.rs
@@ -3,7 +3,7 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 use dom::bindings::codegen::DocumentBinding;
-use dom::bindings::utils::{DOMString, WrapperCache, ErrorResult};
+use dom::bindings::utils::{DOMString, WrapperCache, ErrorResult, Fallible};
 use dom::bindings::utils::{BindingObject, CacheableWrapper, DerivedWrapper};
 use dom::bindings::utils::{is_valid_element_name, InvalidCharacter, Traceable, null_str_as_empty};
 use dom::element::{Element};
@@ -104,14 +104,14 @@ impl Document {
         }
     }
 
-    pub fn Constructor(owner: @mut Window, _rv: &mut ErrorResult) -> AbstractDocument {
+    pub fn Constructor(owner: @mut Window) -> Fallible<AbstractDocument> {
         let root = @HTMLHtmlElement {
             parent: HTMLElement::new(HTMLHtmlElementTypeId, ~"html")
         };
 
         let cx = owner.page.js_info.get_ref().js_compartment.cx.ptr;
         let root = unsafe { Node::as_abstract_node(cx, root) };
-        AbstractDocument::as_abstract(cx, @mut Document::new(root, None, XML))
+        Ok(AbstractDocument::as_abstract(cx, @mut Document::new(root, None, XML)))
     }
 }
 
@@ -242,19 +242,17 @@ impl Document {
         None
     }
 
-    pub fn CreateElement(&self, local_name: &DOMString, rv: &mut ErrorResult) -> AbstractNode<ScriptView> {
+    pub fn CreateElement(&self, local_name: &DOMString) -> Fallible<AbstractNode<ScriptView>> {
         let cx = self.get_cx();
         let local_name = null_str_as_empty(local_name);
         if !is_valid_element_name(local_name) {
-            *rv = Err(InvalidCharacter);
-            // FIXME #909: what to return here?
-            fail!("invalid character");
+            return Err(InvalidCharacter);
         }
         let local_name = local_name.to_ascii_lower();
-        build_element_from_tag(cx, local_name)
+        Ok(build_element_from_tag(cx, local_name))
     }
 
-    pub fn CreateElementNS(&self, _namespace: &DOMString, _qualified_name: &DOMString, _rv: &mut ErrorResult) -> AbstractNode<ScriptView> {
+    pub fn CreateElementNS(&self, _namespace: &DOMString, _qualified_name: &DOMString) -> Fallible<AbstractNode<ScriptView>> {
         fail!("stub")
     }
 
@@ -263,7 +261,7 @@ impl Document {
         unsafe { Node::as_abstract_node(cx, @Text::new(null_str_as_empty(data))) }
     }
 
-    pub fn CreateEvent(&self, _interface: &DOMString, _rv: &mut ErrorResult) -> @mut Event {
+    pub fn CreateEvent(&self, _interface: &DOMString) -> Fallible<@mut Event> {
         fail!("stub")
     }
 
@@ -312,7 +310,7 @@ impl Document {
         Some(title)
     }
 
-    pub fn SetTitle(&self, title: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetTitle(&self, title: &DOMString) -> ErrorResult {
         match self.doctype {
             SVG => {
                 fail!("no SVG document yet")
@@ -349,6 +347,7 @@ impl Document {
                 };
             }
         }
+        Ok(())
     }
 
     pub fn Dir(&self) -> DOMString {
@@ -366,8 +365,8 @@ impl Document {
         None
     }
 
-    pub fn HasFocus(&self, _rv: &mut ErrorResult) -> bool {
-        false
+    pub fn HasFocus(&self) -> Fallible<bool> {
+        Ok(false)
     }
 
     pub fn GetCurrentScript(&self) -> Option<AbstractNode<ScriptView>> {
@@ -381,8 +380,8 @@ impl Document {
         false
     }
 
-    pub fn GetMozFullScreenElement(&self, _rv: &mut ErrorResult) -> Option<AbstractNode<ScriptView>> {
-        None
+    pub fn GetMozFullScreenElement(&self) -> Fallible<Option<AbstractNode<ScriptView>>> {
+        Ok(None)
     }
 
     pub fn GetMozPointerLockElement(&self) -> Option<AbstractNode<ScriptView>> {
@@ -430,8 +429,8 @@ impl Document {
         None
     }
 
-    pub fn QuerySelector(&self, _selectors: &DOMString, _rv: &mut ErrorResult) -> Option<AbstractNode<ScriptView>> {
-        None
+    pub fn QuerySelector(&self, _selectors: &DOMString) -> Fallible<Option<AbstractNode<ScriptView>>> {
+        Ok(None)
     }
 
     pub fn GetElementsByName(&self, name: &DOMString) -> @mut HTMLCollection {
diff --git a/src/components/script/dom/domparser.rs b/src/components/script/dom/domparser.rs
index df8d275a07e..c28dc723218 100644
--- a/src/components/script/dom/domparser.rs
+++ b/src/components/script/dom/domparser.rs
@@ -4,7 +4,7 @@
 
 use dom::bindings::codegen::DOMParserBinding;
 use dom::bindings::codegen::DOMParserBinding::SupportedTypeValues::{Text_html, Text_xml};
-use dom::bindings::utils::{DOMString, ErrorResult, WrapperCache, CacheableWrapper};
+use dom::bindings::utils::{DOMString, Fallible, WrapperCache, CacheableWrapper};
 use dom::document::{AbstractDocument, Document, XML};
 use dom::element::HTMLHtmlElementTypeId;
 use dom::htmldocument::HTMLDocument;
@@ -33,15 +33,14 @@ impl DOMParser {
         parser
     }
 
-    pub fn Constructor(owner: @mut Window, _rv: &mut ErrorResult) -> @mut DOMParser {
-        DOMParser::new(owner)
+    pub fn Constructor(owner: @mut Window) -> Fallible<@mut DOMParser> {
+        Ok(DOMParser::new(owner))
     }
 
     pub fn ParseFromString(&self,
                            _s: &DOMString,
-                           ty: DOMParserBinding::SupportedType,
-                           _rv: &mut ErrorResult)
-                           -> AbstractDocument {
+                           ty: DOMParserBinding::SupportedType)
+                           -> Fallible<AbstractDocument> {
         unsafe {
             let root = @HTMLHtmlElement {
                 parent: HTMLElement::new(HTMLHtmlElementTypeId, ~"html")
@@ -52,10 +51,10 @@ impl DOMParser {
 
             match ty {
                 Text_html => {
-                    HTMLDocument::new(root, None)
+                    Ok(HTMLDocument::new(root, None))
                 }
                 Text_xml => {
-                    AbstractDocument::as_abstract(cx, @mut Document::new(root, None, XML))
+                    Ok(AbstractDocument::as_abstract(cx, @mut Document::new(root, None, XML)))
                 }
                 _ => {
                     fail!("unsupported document type")
diff --git a/src/components/script/dom/element.rs b/src/components/script/dom/element.rs
index 3fbcde1ed9a..520e57ec0d1 100644
--- a/src/components/script/dom/element.rs
+++ b/src/components/script/dom/element.rs
@@ -4,7 +4,7 @@
 
 //! Element nodes.
 
-use dom::bindings::utils::{BindingObject, CacheableWrapper, DOMString, ErrorResult, WrapperCache};
+use dom::bindings::utils::{BindingObject, CacheableWrapper, DOMString, ErrorResult, Fallible, WrapperCache};
 use dom::bindings::utils::{null_str_as_empty, null_str_as_empty_ref};
 use dom::htmlcollection::HTMLCollection;
 use dom::clientrect::ClientRect;
@@ -219,20 +219,21 @@ impl Element {
     pub fn SetAttribute(&mut self,
                         abstract_self: AbstractNode<ScriptView>,
                         name: &DOMString,
-                        value: &DOMString,
-                        _rv: &mut ErrorResult) {
+                        value: &DOMString) -> ErrorResult {
         self.set_attr(abstract_self, name, value);
+        Ok(())
     }
 
-    pub fn SetAttributeNS(&self, _namespace: &DOMString, _localname: &DOMString, _value: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetAttributeNS(&self, _namespace: &DOMString, _localname: &DOMString, _value: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
-    pub fn RemoveAttribute(&self, _name: &DOMString, _rv: &mut ErrorResult) -> bool {
-        false
+    pub fn RemoveAttribute(&self, _name: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
-    pub fn RemoveAttributeNS(&self, _namespace: &DOMString, _localname: &DOMString, _rv: &mut ErrorResult) -> bool {
-        false
+    pub fn RemoveAttributeNS(&self, _namespace: &DOMString, _localname: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn HasAttribute(&self, _name: &DOMString) -> bool {
@@ -248,9 +249,9 @@ impl Element {
         HTMLCollection::new(~[], cx, scope)
     }
 
-    pub fn GetElementsByTagNameNS(&self, _namespace: &DOMString, _localname: &DOMString, _rv: &mut ErrorResult) -> @mut HTMLCollection {
+    pub fn GetElementsByTagNameNS(&self, _namespace: &DOMString, _localname: &DOMString) -> Fallible<@mut HTMLCollection> {
         let (scope, cx) = self.get_scope_and_cx();
-        HTMLCollection::new(~[], cx, scope)
+        Ok(HTMLCollection::new(~[], cx, scope))
     }
 
     pub fn GetElementsByClassName(&self, _names: &DOMString) -> @mut HTMLCollection {
@@ -258,8 +259,8 @@ impl Element {
         HTMLCollection::new(~[], cx, scope)
     }
 
-    pub fn MozMatchesSelector(&self, _selector: &DOMString, _rv: &mut ErrorResult) -> bool {
-        false
+    pub fn MozMatchesSelector(&self, _selector: &DOMString) -> Fallible<bool> {
+        Ok(false)
     }
 
     pub fn SetCapture(&self, _retargetToElement: bool) {
@@ -388,25 +389,28 @@ impl Element {
         0
     }
 
-    pub fn GetInnerHTML(&self, _rv: &mut ErrorResult) -> DOMString {
-        None
+    pub fn GetInnerHTML(&self) -> Fallible<DOMString> {
+        Ok(None)
     }
 
-    pub fn SetInnerHTML(&mut self, _value: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetInnerHTML(&mut self, _value: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
-    pub fn GetOuterHTML(&self, _rv: &mut ErrorResult) -> DOMString {
-        None
+    pub fn GetOuterHTML(&self) -> Fallible<DOMString> {
+        Ok(None)
     }
 
-    pub fn SetOuterHTML(&mut self, _value: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetOuterHTML(&mut self, _value: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
-    pub fn InsertAdjacentHTML(&mut self, _position: &DOMString, _text: &DOMString, _rv: &mut ErrorResult) {
+    pub fn InsertAdjacentHTML(&mut self, _position: &DOMString, _text: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
-    pub fn QuerySelector(&self, _selectors: &DOMString, _rv: &mut ErrorResult) -> Option<AbstractNode<ScriptView>> {
-        None
+    pub fn QuerySelector(&self, _selectors: &DOMString) -> Fallible<Option<AbstractNode<ScriptView>>> {
+        Ok(None)
     }
 }
 
diff --git a/src/components/script/dom/event.rs b/src/components/script/dom/event.rs
index b8e17706c07..745bd323581 100644
--- a/src/components/script/dom/event.rs
+++ b/src/components/script/dom/event.rs
@@ -6,7 +6,7 @@ use dom::eventtarget::EventTarget;
 use dom::window::Window;
 use dom::bindings::codegen::EventBinding;
 use dom::bindings::utils::{CacheableWrapper, BindingObject, DerivedWrapper};
-use dom::bindings::utils::{DOMString, ErrorResult, WrapperCache};
+use dom::bindings::utils::{DOMString, ErrorResult, Fallible, WrapperCache};
 
 use geom::point::Point2D;
 use js::glue::RUST_OBJECT_TO_JSVAL;
@@ -95,11 +95,11 @@ impl Event {
     pub fn InitEvent(&mut self,
                      type_: &DOMString,
                      bubbles: bool,
-                     cancelable: bool,
-                     _rv: &mut ErrorResult) {
+                     cancelable: bool) -> ErrorResult {
         self.type_ = (*type_).clone();
         self.cancelable = cancelable;
         self.bubbles = bubbles;
+        Ok(())
     }
 
     pub fn IsTrusted(&self) -> bool {
@@ -108,9 +108,8 @@ impl Event {
 
     pub fn Constructor(_global: @mut Window,
                    type_: &DOMString,
-                   _init: &EventBinding::EventInit,
-                   _rv: &mut ErrorResult) -> @mut Event {
-        @mut Event::new(type_)
+                   _init: &EventBinding::EventInit) -> Fallible<@mut Event> {
+        Ok(@mut Event::new(type_))
     }
 }
 
diff --git a/src/components/script/dom/htmlanchorelement.rs b/src/components/script/dom/htmlanchorelement.rs
index 7c5b6dcc4ee..d8bac8176ee 100644
--- a/src/components/script/dom/htmlanchorelement.rs
+++ b/src/components/script/dom/htmlanchorelement.rs
@@ -14,90 +14,103 @@ impl HTMLAnchorElement {
         None
     }
 
-    pub fn SetHref(&mut self, _href: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetHref(&mut self, _href: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Target(&self) -> DOMString {
         None
     }
 
-    pub fn SetTarget(&self, _target: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetTarget(&self, _target: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Download(&self) -> DOMString {
         None
     }
 
-    pub fn SetDownload(&self, _download: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetDownload(&self, _download: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Ping(&self) -> DOMString {
         None
     }
 
-    pub fn SetPing(&self, _ping: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetPing(&self, _ping: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Rel(&self) -> DOMString {
         None
     }
 
-    pub fn SetRel(&self, _rel: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetRel(&self, _rel: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Hreflang(&self) -> DOMString {
         None
     }
 
-    pub fn SetHreflang(&self, _href_lang: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetHreflang(&self, _href_lang: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Type(&self) -> DOMString {
         None
     }
 
-    pub fn SetType(&mut self, _type: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetType(&mut self, _type: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Text(&self) -> DOMString {
         None
     }
 
-    pub fn SetText(&mut self, _text: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetText(&mut self, _text: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Coords(&self) -> DOMString {
         None
     }
 
-    pub fn SetCoords(&mut self, _coords: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetCoords(&mut self, _coords: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Charset(&self) -> DOMString {
         None
     }
 
-    pub fn SetCharset(&mut self, _charset: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetCharset(&mut self, _charset: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Name(&self) -> DOMString {
         None
     }
 
-    pub fn SetName(&mut self, _name: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetName(&mut self, _name: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Rev(&self) -> DOMString {
         None
     }
 
-    pub fn SetRev(&mut self, _rev: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetRev(&mut self, _rev: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Shape(&self) -> DOMString {
         None
     }
 
-    pub fn SetShape(&mut self, _shape: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetShape(&mut self, _shape: &DOMString) -> ErrorResult {
+        Ok(())
     }
 }
diff --git a/src/components/script/dom/htmlappletelement.rs b/src/components/script/dom/htmlappletelement.rs
index 0c1deee508c..187c6635440 100644
--- a/src/components/script/dom/htmlappletelement.rs
+++ b/src/components/script/dom/htmlappletelement.rs
@@ -14,76 +14,87 @@ impl HTMLAppletElement {
         None
     }
 
-    pub fn SetAlign(&mut self, _align: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetAlign(&mut self, _align: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Alt(&self) -> DOMString {
         None
     }
 
-    pub fn SetAlt(&self, _alt: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetAlt(&self, _alt: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Archive(&self) -> DOMString {
         None
     }
 
-    pub fn SetArchive(&self, _archive: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetArchive(&self, _archive: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Code(&self) -> DOMString {
         None
     }
 
-    pub fn SetCode(&self, _code: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetCode(&self, _code: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn CodeBase(&self) -> DOMString {
         None
     }
 
-    pub fn SetCodeBase(&self, _code_base: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetCodeBase(&self, _code_base: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Height(&self) -> DOMString {
         None
     }
 
-    pub fn SetHeight(&self, _height: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetHeight(&self, _height: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Hspace(&self) -> u32 {
         0
     }
 
-    pub fn SetHspace(&mut self, _hspace: u32, _rv: &mut ErrorResult) {
+    pub fn SetHspace(&mut self, _hspace: u32) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Name(&self) -> DOMString {
         None
     }
 
-    pub fn SetName(&mut self, _name: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetName(&mut self, _name: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Object(&self) -> DOMString {
         None
     }
 
-    pub fn SetObject(&mut self, _object: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetObject(&mut self, _object: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Vspace(&self) -> u32 {
         0
     }
 
-    pub fn SetVspace(&mut self, _vspace: u32, _rv: &mut ErrorResult) {
+    pub fn SetVspace(&mut self, _vspace: u32) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Width(&self) -> DOMString {
         None
     }
 
-    pub fn SetWidth(&mut self, _width: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetWidth(&mut self, _width: &DOMString) -> ErrorResult {
+        Ok(())
     }
 }
diff --git a/src/components/script/dom/htmlareaelement.rs b/src/components/script/dom/htmlareaelement.rs
index f28de8a6909..df5fe4fce81 100644
--- a/src/components/script/dom/htmlareaelement.rs
+++ b/src/components/script/dom/htmlareaelement.rs
@@ -14,55 +14,63 @@ impl HTMLAreaElement {
         None
     }
 
-    pub fn SetAlt(&self, _alt: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetAlt(&self, _alt: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Coords(&self) -> DOMString {
         None
     }
 
-    pub fn SetCoords(&self, _coords: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetCoords(&self, _coords: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Shape(&self) -> DOMString {
         None
     }
 
-    pub fn SetShape(&self, _shape: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetShape(&self, _shape: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Href(&self) -> DOMString {
         None
     }
 
-    pub fn SetHref(&self, _href: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetHref(&self, _href: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Target(&self) -> DOMString {
         None
     }
 
-    pub fn SetTarget(&self, _target: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetTarget(&self, _target: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Download(&self) -> DOMString {
         None
     }
 
-    pub fn SetDownload(&self, _download: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetDownload(&self, _download: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Ping(&self) -> DOMString {
         None
     }
 
-    pub fn SetPing(&self, _ping: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetPing(&self, _ping: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn NoHref(&self) -> bool {
         false
     }
 
-    pub fn SetNoHref(&mut self, _no_href: bool, _rv: &mut ErrorResult) {
+    pub fn SetNoHref(&mut self, _no_href: bool) -> ErrorResult {
+        Ok(())
     }
 }
diff --git a/src/components/script/dom/htmlbaseelement.rs b/src/components/script/dom/htmlbaseelement.rs
index 67950190616..78168507533 100644
--- a/src/components/script/dom/htmlbaseelement.rs
+++ b/src/components/script/dom/htmlbaseelement.rs
@@ -14,13 +14,15 @@ impl HTMLBaseElement {
         None
     }
 
-    pub fn SetHref(&self, _href: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetHref(&self, _href: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Target(&self) -> DOMString {
         None
     }
 
-    pub fn SetTarget(&self, _target: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetTarget(&self, _target: &DOMString) -> ErrorResult {
+        Ok(())
     }
 }
diff --git a/src/components/script/dom/htmlbodyelement.rs b/src/components/script/dom/htmlbodyelement.rs
index 6d305f45bc3..85918884793 100644
--- a/src/components/script/dom/htmlbodyelement.rs
+++ b/src/components/script/dom/htmlbodyelement.rs
@@ -14,41 +14,47 @@ impl HTMLBodyElement {
         None
     }
 
-    pub fn SetText(&mut self, _text: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetText(&mut self, _text: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Link(&self) -> DOMString {
         None
     }
 
-    pub fn SetLink(&self, _link: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetLink(&self, _link: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn VLink(&self) -> DOMString {
         None
     }
 
-    pub fn SetVLink(&self, _v_link: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetVLink(&self, _v_link: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn ALink(&self) -> DOMString {
         None
     }
 
-    pub fn SetALink(&self, _a_link: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetALink(&self, _a_link: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn BgColor(&self) -> DOMString {
         None
     }
 
-    pub fn SetBgColor(&self, _bg_color: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetBgColor(&self, _bg_color: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Background(&self) -> DOMString {
         None
     }
 
-    pub fn SetBackground(&self, _background: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetBackground(&self, _background: &DOMString) -> ErrorResult {
+        Ok(())
     }
 }
diff --git a/src/components/script/dom/htmlbrelement.rs b/src/components/script/dom/htmlbrelement.rs
index faa7f1d758b..164d8d13176 100644
--- a/src/components/script/dom/htmlbrelement.rs
+++ b/src/components/script/dom/htmlbrelement.rs
@@ -14,6 +14,7 @@ impl HTMLBRElement {
         None
     }
 
-    pub fn SetClear(&mut self, _text: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetClear(&mut self, _text: &DOMString) -> ErrorResult {
+        Ok(())
     }
 }
diff --git a/src/components/script/dom/htmlbuttonelement.rs b/src/components/script/dom/htmlbuttonelement.rs
index c2e3fd1f3f2..dbc84a6e4a3 100644
--- a/src/components/script/dom/htmlbuttonelement.rs
+++ b/src/components/script/dom/htmlbuttonelement.rs
@@ -16,14 +16,16 @@ impl HTMLButtonElement {
         false
     }
 
-    pub fn SetAutofocus(&mut self, _autofocus: bool, _rv: &mut ErrorResult) {
+    pub fn SetAutofocus(&mut self, _autofocus: bool) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Disabled(&self) -> bool {
         false
     }
 
-    pub fn SetDisabled(&mut self, _disabled: bool, _rv: &mut ErrorResult) {
+    pub fn SetDisabled(&mut self, _disabled: bool) -> ErrorResult {
+        Ok(())
     }
 
     pub fn GetForm(&self) -> Option<AbstractNode<ScriptView>> {
@@ -34,56 +36,64 @@ impl HTMLButtonElement {
         None
     }
 
-    pub fn SetFormAction(&mut self, _formaction: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetFormAction(&mut self, _formaction: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn FormEnctype(&self) -> DOMString {
         None
     }
 
-    pub fn SetFormEnctype(&mut self, _formenctype: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetFormEnctype(&mut self, _formenctype: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn FormMethod(&self) -> DOMString {
         None
     }
 
-    pub fn SetFormMethod(&mut self, _formmethod: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetFormMethod(&mut self, _formmethod: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn FormNoValidate(&self) -> bool {
         false
     }
 
-    pub fn SetFormNoValidate(&mut self, _novalidate: bool, _rv: &mut ErrorResult) {
+    pub fn SetFormNoValidate(&mut self, _novalidate: bool) -> ErrorResult {
+        Ok(())
     }
 
     pub fn FormTarget(&self) -> DOMString {
         None
     }
 
-    pub fn SetFormTarget(&mut self, _formtarget: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetFormTarget(&mut self, _formtarget: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Name(&self) -> DOMString {
         None
     }
 
-    pub fn SetName(&mut self, _name: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetName(&mut self, _name: &DOMString) -> ErrorResult {
+        Ok(())
     }
     
     pub fn Type(&self) -> DOMString {
         None
     }
 
-    pub fn SetType(&mut self, _type: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetType(&mut self, _type: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Value(&self) -> DOMString {
         None
     }
 
-    pub fn SetValue(&mut self, _value: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetValue(&mut self, _value: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn WillValidate(&self) -> bool {
@@ -104,7 +114,8 @@ impl HTMLButtonElement {
         None
     }
 
-    pub fn SetValidationMessage(&mut self, _message: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetValidationMessage(&mut self, _message: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn CheckValidity(&self) -> bool {
@@ -113,4 +124,4 @@ impl HTMLButtonElement {
 
     pub fn SetCustomValidity(&mut self, _error: &DOMString) {
     }
-}
\ No newline at end of file
+}
diff --git a/src/components/script/dom/htmlcanvaselement.rs b/src/components/script/dom/htmlcanvaselement.rs
index fd2caad56ce..1afcbc667ec 100644
--- a/src/components/script/dom/htmlcanvaselement.rs
+++ b/src/components/script/dom/htmlcanvaselement.rs
@@ -14,13 +14,15 @@ impl HTMLCanvasElement {
         0
     }
 
-    pub fn SetWidth(&mut self, _width: u32, _rv: &mut ErrorResult) {
+    pub fn SetWidth(&mut self, _width: u32) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Height(&self) -> u32 {
         0
     }
 
-    pub fn SetHeight(&mut self, _height: u32, _rv: &mut ErrorResult) {
+    pub fn SetHeight(&mut self, _height: u32) -> ErrorResult {
+        Ok(())
     }
 }
diff --git a/src/components/script/dom/htmlcollection.rs b/src/components/script/dom/htmlcollection.rs
index db668d70e64..a16b2090355 100644
--- a/src/components/script/dom/htmlcollection.rs
+++ b/src/components/script/dom/htmlcollection.rs
@@ -4,7 +4,7 @@
 
 use dom::bindings::codegen::HTMLCollectionBinding;
 use dom::bindings::utils::{CacheableWrapper, BindingObject, WrapperCache};
-use dom::bindings::utils::{DOMString, ErrorResult};
+use dom::bindings::utils::{DOMString, Fallible};
 use dom::node::{AbstractNode, ScriptView};
 use script_task::page_from_context;
 
@@ -44,9 +44,8 @@ impl HTMLCollection {
         }
     }
 
-    pub fn NamedItem(&self, _cx: *JSContext, _name: &DOMString, rv: &mut ErrorResult) -> *JSObject {
-        *rv = Ok(());
-        ptr::null()
+    pub fn NamedItem(&self, _cx: *JSContext, _name: &DOMString) -> Fallible<*JSObject> {
+        Ok(ptr::null())
     }
 
     pub fn IndexedGetter(&self, index: u32, found: &mut bool) -> Option<AbstractNode<ScriptView>> {
@@ -54,8 +53,8 @@ impl HTMLCollection {
         self.Item(index)
     }
 
-    pub fn NamedGetter(&self, _cx: *JSContext, _name: &DOMString, _found: &mut bool, _rv: &mut ErrorResult) -> *JSObject {
-        ptr::null()
+    pub fn NamedGetter(&self, _cx: *JSContext, _name: &DOMString, _found: &mut bool) -> Fallible<*JSObject> {
+        Ok(ptr::null())
     }
 }
 
diff --git a/src/components/script/dom/htmldataelement.rs b/src/components/script/dom/htmldataelement.rs
index d90007af17e..7b175e1853f 100644
--- a/src/components/script/dom/htmldataelement.rs
+++ b/src/components/script/dom/htmldataelement.rs
@@ -14,6 +14,7 @@ impl HTMLDataElement {
         None
     }
 
-    pub fn SetValue(&mut self, _value: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetValue(&mut self, _value: &DOMString) -> ErrorResult {
+        Ok(())
     }
 }
diff --git a/src/components/script/dom/htmldirectoryelement.rs b/src/components/script/dom/htmldirectoryelement.rs
index 2c6899745fb..2d5eb5fd48d 100644
--- a/src/components/script/dom/htmldirectoryelement.rs
+++ b/src/components/script/dom/htmldirectoryelement.rs
@@ -14,6 +14,7 @@ impl HTMLDirectoryElement {
         false
     }
 
-    pub fn SetCompact(&mut self, _compact: bool, _rv: &mut ErrorResult) {
+    pub fn SetCompact(&mut self, _compact: bool) -> ErrorResult {
+        Ok(())
     }
-}
\ No newline at end of file
+}
diff --git a/src/components/script/dom/htmldivelement.rs b/src/components/script/dom/htmldivelement.rs
index a9af75f17e9..d626873251e 100644
--- a/src/components/script/dom/htmldivelement.rs
+++ b/src/components/script/dom/htmldivelement.rs
@@ -14,6 +14,7 @@ impl HTMLDivElement {
         None
     }
 
-    pub fn SetAlign(&mut self, _align: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetAlign(&mut self, _align: &DOMString) -> ErrorResult {
+        Ok(())
     }
 }
diff --git a/src/components/script/dom/htmldlistelement.rs b/src/components/script/dom/htmldlistelement.rs
index 87c51145d38..6ce58ba1195 100644
--- a/src/components/script/dom/htmldlistelement.rs
+++ b/src/components/script/dom/htmldlistelement.rs
@@ -14,13 +14,15 @@ impl HTMLDListElement {
         false
     }
 
-    pub fn SetCompact(&mut self, _compact: bool, _rv: &mut ErrorResult) {
+    pub fn SetCompact(&mut self, _compact: bool) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Type(&self) -> DOMString {
         None
     }
 
-    pub fn SetType(&mut self, _type: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetType(&mut self, _type: &DOMString) -> ErrorResult {
+        Ok(())
     }
 }
diff --git a/src/components/script/dom/htmldocument.rs b/src/components/script/dom/htmldocument.rs
index 037ba0cf8a2..855231ea637 100644
--- a/src/components/script/dom/htmldocument.rs
+++ b/src/components/script/dom/htmldocument.rs
@@ -3,7 +3,7 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 use dom::bindings::codegen::HTMLDocumentBinding;
-use dom::bindings::utils::{DOMString, ErrorResult};
+use dom::bindings::utils::{DOMString, ErrorResult, Fallible};
 use dom::bindings::utils::{CacheableWrapper, BindingObject, WrapperCache};
 use dom::document::{AbstractDocument, Document, WrappableDocument, HTML};
 use dom::element::HTMLHeadElementTypeId;
@@ -49,22 +49,24 @@ impl WrappableDocument for HTMLDocument {
 }
 
 impl HTMLDocument {
-    pub fn NamedGetter(&self, _cx: *JSContext, _name: &DOMString, _found: &mut bool, _rv: &mut ErrorResult) -> *JSObject {
-        ptr::null()
+    pub fn NamedGetter(&self, _cx: *JSContext, _name: &DOMString, _found: &mut bool) -> Fallible<*JSObject> {
+        Ok(ptr::null())
     }
 
-    pub fn GetDomain(&self, _rv: &mut ErrorResult) -> DOMString {
-        None
+    pub fn GetDomain(&self) -> Fallible<DOMString> {
+        Ok(None)
     }
 
-    pub fn SetDomain(&self, _domain: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetDomain(&self, _domain: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
-    pub fn GetCookie(&self, _rv: &mut ErrorResult) -> DOMString {
-        None
+    pub fn GetCookie(&self) -> Fallible<DOMString> {
+        Ok(None)
     }
 
-    pub fn SetCookie(&self, _cookie: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetCookie(&self, _cookie: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn GetHead(&self) -> Option<AbstractNode<ScriptView>> {
@@ -104,38 +106,40 @@ impl HTMLDocument {
         self.parent.createHTMLCollection(|elem| eq_slice(elem.tag_name, "script"))
     }
 
-    pub fn Close(&self, _rv: &mut ErrorResult) {
+    pub fn Close(&self) -> ErrorResult {
+        Ok(())
     }
 
     pub fn DesignMode(&self) -> DOMString {
         None
     }
 
-    pub fn SetDesignMode(&self, _mode: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetDesignMode(&self, _mode: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
-    pub fn ExecCommand(&self, _command_id: &DOMString, _show_ui: bool, _value: &DOMString, _rv: &mut ErrorResult) -> bool {
-        false
+    pub fn ExecCommand(&self, _command_id: &DOMString, _show_ui: bool, _value: &DOMString) -> Fallible<bool> {
+        Ok(false)
     }
 
-    pub fn QueryCommandEnabled(&self, _command_id: &DOMString, _rv: &mut ErrorResult) -> bool {
-        false
+    pub fn QueryCommandEnabled(&self, _command_id: &DOMString) -> Fallible<bool> {
+        Ok(false)
     }
 
-    pub fn QueryCommandIndeterm(&self, _command_id: &DOMString, _rv: &mut ErrorResult) -> bool {
-        false
+    pub fn QueryCommandIndeterm(&self, _command_id: &DOMString) -> Fallible<bool> {
+        Ok(false)
     }
 
-    pub fn QueryCommandState(&self, _command_id: &DOMString, _rv: &mut ErrorResult) -> bool {
-        false
+    pub fn QueryCommandState(&self, _command_id: &DOMString) -> Fallible<bool> {
+        Ok(false)
     }
 
     pub fn QueryCommandSupported(&self, _command_id: &DOMString) -> bool {
         false
     }
 
-    pub fn QueryCommandValue(&self, _command_id: &DOMString, _rv: &mut ErrorResult) -> DOMString {
-        None
+    pub fn QueryCommandValue(&self, _command_id: &DOMString) -> Fallible<DOMString> {
+        Ok(None)
     }
 
     pub fn FgColor(&self) -> DOMString {
@@ -186,8 +190,8 @@ impl HTMLDocument {
     pub fn Clear(&self) {
     }
 
-    pub fn GetAll(&self, _cx: *JSContext, _rv: &mut ErrorResult) -> *libc::c_void {
-        ptr::null()
+    pub fn GetAll(&self, _cx: *JSContext) -> Fallible<*libc::c_void> {
+        Ok(ptr::null())
     }
 }
 
diff --git a/src/components/script/dom/htmlelement.rs b/src/components/script/dom/htmlelement.rs
index 80ec901e657..7dcb43aad5e 100644
--- a/src/components/script/dom/htmlelement.rs
+++ b/src/components/script/dom/htmlelement.rs
@@ -3,7 +3,7 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 use dom::bindings::codegen::HTMLElementBinding;
-use dom::bindings::utils::{DOMString, ErrorResult};
+use dom::bindings::utils::{DOMString, ErrorResult, Fallible};
 use dom::bindings::utils::{CacheableWrapper, BindingObject, WrapperCache};
 use dom::element::{Element, ElementTypeId};
 use dom::node::{AbstractNode, ScriptView};
@@ -41,21 +41,24 @@ impl HTMLElement {
         None
     }
 
-    pub fn SetDir(&mut self, _dir: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetDir(&mut self, _dir: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
-    pub fn GetItemValue(&self, _cx: *JSContext, _rv: &mut ErrorResult) -> JSVal {
-        JSVAL_NULL
+    pub fn GetItemValue(&self, _cx: *JSContext) -> Fallible<JSVal> {
+        Ok(JSVAL_NULL)
     }
 
-    pub fn SetItemValue(&mut self, _cx: *JSContext, _val: JSVal, _rv: &mut ErrorResult) {
+    pub fn SetItemValue(&mut self, _cx: *JSContext, _val: JSVal) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Hidden(&self) -> bool {
         false
     }
 
-    pub fn SetHidden(&mut self, _hidden: bool, _rv: &mut ErrorResult) {
+    pub fn SetHidden(&mut self, _hidden: bool) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Click(&self) {
@@ -65,20 +68,24 @@ impl HTMLElement {
         0
     }
 
-    pub fn SetTabIndex(&mut self, _index: i32, _rv: &mut ErrorResult) {
+    pub fn SetTabIndex(&mut self, _index: i32) -> ErrorResult {
+        Ok(())
     }
 
-    pub fn Focus(&self, _rv: &mut ErrorResult) {
+    pub fn Focus(&self) -> ErrorResult {
+        Ok(())
     }
 
-    pub fn Blur(&self, _rv: &mut ErrorResult) {
+    pub fn Blur(&self) -> ErrorResult {
+        Ok(())
     }
 
     pub fn AccessKey(&self) -> DOMString {
         None
     }
 
-    pub fn SetAccessKey(&self, _key: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetAccessKey(&self, _key: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn AccessKeyLabel(&self) -> DOMString {
@@ -89,14 +96,16 @@ impl HTMLElement {
         false
     }
 
-    pub fn SetDraggable(&mut self, _draggable: bool, _rv: &mut ErrorResult) {
+    pub fn SetDraggable(&mut self, _draggable: bool) -> ErrorResult {
+        Ok(())
     }
 
     pub fn ContentEditable(&self) -> DOMString {
         None
     }
 
-    pub fn SetContentEditable(&mut self, _val: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetContentEditable(&mut self, _val: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn IsContentEditable(&self) -> bool {
@@ -107,7 +116,8 @@ impl HTMLElement {
         false
     }
 
-    pub fn SetSpellcheck(&self, _val: bool, _rv: &mut ErrorResult) {
+    pub fn SetSpellcheck(&self, _val: bool) -> ErrorResult {
+        Ok(())
     }
 
     pub fn ClassName(&self) -> DOMString {
diff --git a/src/components/script/dom/htmlembedelement.rs b/src/components/script/dom/htmlembedelement.rs
index b5b5e9833d5..0ae3b926eb8 100644
--- a/src/components/script/dom/htmlembedelement.rs
+++ b/src/components/script/dom/htmlembedelement.rs
@@ -15,42 +15,48 @@ impl HTMLEmbedElement {
         None
     }
 
-    pub fn SetSrc(&mut self, _src: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetSrc(&mut self, _src: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Type(&self) -> DOMString {
         None
     }
 
-    pub fn SetType(&mut self, _type: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetType(&mut self, _type: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Width(&self) -> DOMString {
         None
     }
 
-    pub fn SetWidth(&mut self, _width: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetWidth(&mut self, _width: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Height(&self) -> DOMString {
         None
     }
 
-    pub fn SetHeight(&mut self, _height: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetHeight(&mut self, _height: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Align(&self) -> DOMString {
         None
     }
 
-    pub fn SetAlign(&mut self, _type: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetAlign(&mut self, _type: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Name(&self) -> DOMString {
         None
     }
 
-    pub fn SetName(&mut self, _type: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetName(&mut self, _type: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn GetSVGDocument(&self) -> Option<AbstractDocument> {
diff --git a/src/components/script/dom/htmlfieldsetelement.rs b/src/components/script/dom/htmlfieldsetelement.rs
index 42f23dba530..7a8e19b01ef 100644
--- a/src/components/script/dom/htmlfieldsetelement.rs
+++ b/src/components/script/dom/htmlfieldsetelement.rs
@@ -19,7 +19,8 @@ impl HTMLFieldSetElement {
         false
     }
 
-    pub fn SetDisabled(&mut self, _disabled: bool, _rv: &mut ErrorResult) {
+    pub fn SetDisabled(&mut self, _disabled: bool) -> ErrorResult {
+        Ok(())
     }
 
     pub fn GetForm(&self) -> Option<AbstractNode<ScriptView>> {
@@ -30,7 +31,8 @@ impl HTMLFieldSetElement {
         None
     }
 
-    pub fn SetName(&mut self, _name: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetName(&mut self, _name: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Type(&self) -> DOMString {
@@ -69,4 +71,4 @@ impl HTMLFieldSetElement {
 
     pub fn SetCustomValidity(&mut self, _error: &DOMString) {
     }
-}
\ No newline at end of file
+}
diff --git a/src/components/script/dom/htmlfontelement.rs b/src/components/script/dom/htmlfontelement.rs
index 1d1158b6de4..d0152bc7f25 100644
--- a/src/components/script/dom/htmlfontelement.rs
+++ b/src/components/script/dom/htmlfontelement.rs
@@ -14,20 +14,23 @@ impl HTMLFontElement {
         None
     }
 
-    pub fn SetColor(&mut self, _color: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetColor(&mut self, _color: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Face(&self) -> DOMString {
         None
     }
 
-    pub fn SetFace(&mut self, _face: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetFace(&mut self, _face: &DOMString) -> ErrorResult {
+        Ok(())
     }
     
     pub fn Size(&self) -> DOMString {
         None
     }
 
-    pub fn SetSize(&mut self, _size: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetSize(&mut self, _size: &DOMString) -> ErrorResult {
+        Ok(())
     }
 }
diff --git a/src/components/script/dom/htmlformelement.rs b/src/components/script/dom/htmlformelement.rs
index 0b1a8e96a9f..5cfa3e68bfd 100644
--- a/src/components/script/dom/htmlformelement.rs
+++ b/src/components/script/dom/htmlformelement.rs
@@ -28,63 +28,72 @@ impl HTMLFormElement {
         None
     }
 
-    pub fn SetAcceptCharset(&mut self, _accept_charset: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetAcceptCharset(&mut self, _accept_charset: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Action(&self) -> DOMString {
         None
     }
 
-    pub fn SetAction(&mut self, _action: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetAction(&mut self, _action: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Autocomplete(&self) -> DOMString {
         None
     }
 
-    pub fn SetAutocomplete(&mut self, _autocomplete: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetAutocomplete(&mut self, _autocomplete: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Enctype(&self) -> DOMString {
         None
     }
 
-    pub fn SetEnctype(&mut self, _enctype: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetEnctype(&mut self, _enctype: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Encoding(&self) -> DOMString {
         None
     }
 
-    pub fn SetEncoding(&mut self, _encoding: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetEncoding(&mut self, _encoding: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Method(&self) -> DOMString {
         None
     }
 
-    pub fn SetMethod(&mut self, _method: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetMethod(&mut self, _method: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Name(&self) -> DOMString {
         None
     }
 
-    pub fn SetName(&mut self, _name: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetName(&mut self, _name: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn NoValidate(&self) -> bool {
         false
     }
 
-    pub fn SetNoValidate(&mut self, _no_validate: bool, _rv: &mut ErrorResult) {
+    pub fn SetNoValidate(&mut self, _no_validate: bool) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Target(&self) -> DOMString {
         None
     }
 
-    pub fn SetTarget(&mut self, _target: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetTarget(&mut self, _target: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Elements(&self) -> @mut HTMLCollection {
@@ -96,7 +105,8 @@ impl HTMLFormElement {
         0
     }
     
-    pub fn Submit(&self, _rv: &mut ErrorResult) {
+    pub fn Submit(&self) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Reset(&self) {
diff --git a/src/components/script/dom/htmlframeelement.rs b/src/components/script/dom/htmlframeelement.rs
index 4dc263f7cb2..3dd275797be 100644
--- a/src/components/script/dom/htmlframeelement.rs
+++ b/src/components/script/dom/htmlframeelement.rs
@@ -16,42 +16,48 @@ impl HTMLFrameElement {
         None
     }
 
-    pub fn SetName(&mut self, _name: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetName(&mut self, _name: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Scrolling(&self) -> DOMString {
         None
     }
 
-    pub fn SetScrolling(&mut self, _scrolling: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetScrolling(&mut self, _scrolling: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Src(&self) -> DOMString {
         None
     }
 
-    pub fn SetSrc(&mut self, _src: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetSrc(&mut self, _src: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn FrameBorder(&self) -> DOMString {
         None
     }
 
-    pub fn SetFrameBorder(&mut self, _frameborder: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetFrameBorder(&mut self, _frameborder: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn LongDesc(&self) -> DOMString {
         None
     }
 
-    pub fn SetLongDesc(&mut self, _longdesc: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetLongDesc(&mut self, _longdesc: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn NoResize(&self) -> bool {
         false
     }
 
-    pub fn SetNoResize(&mut self, _no_resize: bool, _rv: &mut ErrorResult) {
+    pub fn SetNoResize(&mut self, _no_resize: bool) -> ErrorResult {
+        Ok(())
     }
 
     pub fn GetContentDocument(&self) -> Option<AbstractDocument> {
@@ -66,13 +72,15 @@ impl HTMLFrameElement {
         None
     }
 
-    pub fn SetMarginHeight(&mut self, _height: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetMarginHeight(&mut self, _height: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn MarginWidth(&self) -> DOMString {
         None
     }
 
-    pub fn SetMarginWidth(&mut self, _height: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetMarginWidth(&mut self, _height: &DOMString) -> ErrorResult {
+        Ok(())
     }
-}
\ No newline at end of file
+}
diff --git a/src/components/script/dom/htmlframesetelement.rs b/src/components/script/dom/htmlframesetelement.rs
index eac14207dc0..0660380757b 100644
--- a/src/components/script/dom/htmlframesetelement.rs
+++ b/src/components/script/dom/htmlframesetelement.rs
@@ -14,13 +14,15 @@ impl HTMLFrameSetElement {
         None
     }
 
-    pub fn SetCols(&mut self, _cols: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetCols(&mut self, _cols: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Rows(&self) -> DOMString {
         None
     }
 
-    pub fn SetRows(&mut self, _rows: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetRows(&mut self, _rows: &DOMString) -> ErrorResult {
+        Ok(())
     }
-}
\ No newline at end of file
+}
diff --git a/src/components/script/dom/htmlhrelement.rs b/src/components/script/dom/htmlhrelement.rs
index 95e2b34e3f3..08ce278d2e7 100644
--- a/src/components/script/dom/htmlhrelement.rs
+++ b/src/components/script/dom/htmlhrelement.rs
@@ -14,34 +14,39 @@ impl HTMLHRElement {
         None
     }
 
-    pub fn SetAlign(&mut self, _align: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetAlign(&mut self, _align: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Color(&self) -> DOMString {
         None
     }
 
-    pub fn SetColor(&mut self, _color: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetColor(&mut self, _color: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn NoShade(&self) -> bool {
         false
     }
 
-    pub fn SetNoShade(&self, _no_shade: bool, _rv: &mut ErrorResult) {
+    pub fn SetNoShade(&self, _no_shade: bool) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Size(&self) -> DOMString {
         None
     }
 
-    pub fn SetSize(&mut self, _size: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetSize(&mut self, _size: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Width(&self) -> DOMString {
         None
     }
 
-    pub fn SetWidth(&mut self, _width: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetWidth(&mut self, _width: &DOMString) -> ErrorResult {
+        Ok(())
     }
 }
diff --git a/src/components/script/dom/htmlhtmlelement.rs b/src/components/script/dom/htmlhtmlelement.rs
index 4221f9c679f..7e292c9c557 100644
--- a/src/components/script/dom/htmlhtmlelement.rs
+++ b/src/components/script/dom/htmlhtmlelement.rs
@@ -14,6 +14,7 @@ impl HTMLHtmlElement {
         None
     }
 
-    pub fn SetVersion(&mut self, _version: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetVersion(&mut self, _version: &DOMString) -> ErrorResult {
+        Ok(())
     }
 }
diff --git a/src/components/script/dom/htmliframeelement.rs b/src/components/script/dom/htmliframeelement.rs
index 6a42197b8c6..3ddab8af1ea 100644
--- a/src/components/script/dom/htmliframeelement.rs
+++ b/src/components/script/dom/htmliframeelement.rs
@@ -63,21 +63,24 @@ impl HTMLIFrameElement {
         None
     }
 
-    pub fn SetSrc(&mut self, _src: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetSrc(&mut self, _src: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Srcdoc(&self) -> DOMString {
         None
     }
 
-    pub fn SetSrcdoc(&mut self, _srcdoc: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetSrcdoc(&mut self, _srcdoc: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Name(&self) -> DOMString {
         None
     }
 
-    pub fn SetName(&mut self, _name: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetName(&mut self, _name: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Sandbox(&self, _abstract_self: AbstractNode<ScriptView>) -> DOMString {
@@ -85,8 +88,7 @@ impl HTMLIFrameElement {
     }
 
     pub fn SetSandbox(&mut self, abstract_self: AbstractNode<ScriptView>, sandbox: &DOMString) {
-        let mut rv = Ok(());
-        self.parent.parent.SetAttribute(abstract_self, &Some(~"sandbox"), sandbox, &mut rv);
+        self.parent.parent.SetAttribute(abstract_self, &Some(~"sandbox"), sandbox);
     }
 
     pub fn AfterSetAttr(&mut self, name: &DOMString, value: &DOMString) {
@@ -113,21 +115,24 @@ impl HTMLIFrameElement {
         false
     }
 
-    pub fn SetAllowFullscreen(&mut self, _allow: bool, _rv: &mut ErrorResult) {
+    pub fn SetAllowFullscreen(&mut self, _allow: bool) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Width(&self) -> DOMString {
         None
     }
 
-    pub fn SetWidth(&mut self, _width: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetWidth(&mut self, _width: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Height(&self) -> DOMString {
         None
     }
 
-    pub fn SetHeight(&mut self, _height: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetHeight(&mut self, _height: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn GetContentDocument(&self) -> Option<AbstractDocument> {
@@ -142,42 +147,48 @@ impl HTMLIFrameElement {
         None
     }
 
-    pub fn SetAlign(&mut self, _align: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetAlign(&mut self, _align: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Scrolling(&self) -> DOMString {
         None
     }
 
-    pub fn SetScrolling(&mut self, _scrolling: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetScrolling(&mut self, _scrolling: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn FrameBorder(&self) -> DOMString {
         None
     }
 
-    pub fn SetFrameBorder(&mut self, _frameborder: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetFrameBorder(&mut self, _frameborder: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn LongDesc(&self) -> DOMString {
         None
     }
 
-    pub fn SetLongDesc(&mut self, _longdesc: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetLongDesc(&mut self, _longdesc: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn MarginHeight(&self) -> DOMString {
         None
     }
 
-    pub fn SetMarginHeight(&mut self, _marginheight: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetMarginHeight(&mut self, _marginheight: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn MarginWidth(&self) -> DOMString {
         None
     }
 
-    pub fn SetMarginWidth(&mut self, _marginwidth: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetMarginWidth(&mut self, _marginwidth: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn GetSVGDocument(&self) -> Option<AbstractDocument> {
diff --git a/src/components/script/dom/htmlimageelement.rs b/src/components/script/dom/htmlimageelement.rs
index 84f5d0d7d90..661d14ef891 100644
--- a/src/components/script/dom/htmlimageelement.rs
+++ b/src/components/script/dom/htmlimageelement.rs
@@ -58,7 +58,8 @@ impl HTMLImageElement {
         None
     }
 
-    pub fn SetAlt(&mut self, _alt: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetAlt(&mut self, _alt: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Src(&self, _abstract_self: AbstractNode<ScriptView>) -> DOMString {
@@ -67,33 +68,36 @@ impl HTMLImageElement {
 
     pub fn SetSrc(&mut self,
                   abstract_self: AbstractNode<ScriptView>,
-                  src: &DOMString,
-                  _rv: &mut ErrorResult) {
+                  src: &DOMString) -> ErrorResult {
         let node = &mut self.parent.parent;
         node.set_attr(abstract_self,
                       &Some(~"src"),
                       &Some(null_str_as_empty(src)));
+        Ok(())
     }
 
     pub fn CrossOrigin(&self) -> DOMString {
         None
     }
 
-    pub fn SetCrossOrigin(&mut self, _cross_origin: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetCrossOrigin(&mut self, _cross_origin: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn UseMap(&self) -> DOMString {
         None
     }
 
-    pub fn SetUseMap(&mut self, _use_map: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetUseMap(&mut self, _use_map: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn IsMap(&self) -> bool {
         false
     }
 
-    pub fn SetIsMap(&self, _is_map: bool, _rv: &mut ErrorResult) {
+    pub fn SetIsMap(&self, _is_map: bool) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Width(&self, abstract_self: AbstractNode<ScriptView>) -> u32 {
@@ -125,12 +129,12 @@ impl HTMLImageElement {
 
     pub fn SetWidth(&mut self,
                     abstract_self: AbstractNode<ScriptView>,
-                    width: u32,
-                    _rv: &mut ErrorResult) {
+                    width: u32) -> ErrorResult {
         let node = &mut self.parent.parent;
         node.set_attr(abstract_self,
                       &Some(~"width"),
                       &Some(width.to_str()));
+        Ok(())
     }
 
     pub fn Height(&self, abstract_self: AbstractNode<ScriptView>) -> u32 {
@@ -162,12 +166,12 @@ impl HTMLImageElement {
 
     pub fn SetHeight(&mut self,
                      abstract_self: AbstractNode<ScriptView>,
-                     height: u32,
-                     _rv: &mut ErrorResult) {
+                     height: u32) -> ErrorResult {
         let node = &mut self.parent.parent;
         node.set_attr(abstract_self,
                       &Some(~"height"),
                       &Some(height.to_str()));
+        Ok(())
     }
 
     pub fn NaturalWidth(&self) -> u32 {
@@ -186,41 +190,47 @@ impl HTMLImageElement {
         None
     }
 
-    pub fn SetName(&mut self, _name: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetName(&mut self, _name: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Align(&self) -> DOMString {
         None
     }
 
-    pub fn SetAlign(&mut self, _align: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetAlign(&mut self, _align: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Hspace(&self) -> u32 {
         0
     }
 
-    pub fn SetHspace(&mut self, _hspace: u32, _rv: &mut ErrorResult) {
+    pub fn SetHspace(&mut self, _hspace: u32) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Vspace(&self) -> u32 {
         0
     }
 
-    pub fn SetVspace(&mut self, _vspace: u32, _rv: &mut ErrorResult) {
+    pub fn SetVspace(&mut self, _vspace: u32) -> ErrorResult {
+        Ok(())
     }
 
     pub fn LongDesc(&self) -> DOMString {
         None
     }
 
-    pub fn SetLongDesc(&mut self, _longdesc: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetLongDesc(&mut self, _longdesc: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Border(&self) -> DOMString {
         None
     }
 
-    pub fn SetBorder(&mut self, _border: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetBorder(&mut self, _border: &DOMString) -> ErrorResult {
+        Ok(())
     }
 }
diff --git a/src/components/script/dom/htmlinputelement.rs b/src/components/script/dom/htmlinputelement.rs
index 415de3ae32c..abf4b0b470a 100644
--- a/src/components/script/dom/htmlinputelement.rs
+++ b/src/components/script/dom/htmlinputelement.rs
@@ -2,7 +2,7 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-use dom::bindings::utils::{DOMString, ErrorResult};
+use dom::bindings::utils::{DOMString, ErrorResult, Fallible};
 use dom::htmlelement::HTMLElement;
 
 pub struct HTMLInputElement {
@@ -14,35 +14,40 @@ impl HTMLInputElement {
         None
     }
 
-    pub fn SetAccept(&mut self, _accept: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetAccept(&mut self, _accept: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Alt(&self) -> DOMString {
         None
     }
 
-    pub fn SetAlt(&mut self, _alt: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetAlt(&mut self, _alt: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Autocomplete(&self) -> DOMString {
         None
     }
 
-    pub fn SetAutocomplete(&mut self, _autocomple: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetAutocomplete(&mut self, _autocomple: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Autofocus(&self) -> bool {
         false
     }
 
-    pub fn SetAutofocus(&mut self, _autofocus: bool, _rv: &mut ErrorResult) {
+    pub fn SetAutofocus(&mut self, _autofocus: bool) -> ErrorResult {
+        Ok(())
     }
 
     pub fn DefaultChecked(&self) -> bool {
         false
     }
 
-    pub fn SetDefaultChecked(&mut self, _default_checked: bool, _rv: &mut ErrorResult) {
+    pub fn SetDefaultChecked(&mut self, _default_checked: bool) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Checked(&self) -> bool {
@@ -56,49 +61,56 @@ impl HTMLInputElement {
         false
     }
 
-    pub fn SetDisabled(&mut self, _disabled: bool, _rv: &mut ErrorResult) {
+    pub fn SetDisabled(&mut self, _disabled: bool) -> ErrorResult {
+        Ok(())
     }
 
     pub fn FormAction(&self) -> DOMString {
         None
     }
 
-    pub fn SetFormAction(&mut self, _form_action: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetFormAction(&mut self, _form_action: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn FormEnctype(&self) -> DOMString {
         None
     }
 
-    pub fn SetFormEnctype(&mut self, _form_enctype: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetFormEnctype(&mut self, _form_enctype: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn FormMethod(&self) -> DOMString {
         None
     }
 
-    pub fn SetFormMethod(&mut self, _form_method: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetFormMethod(&mut self, _form_method: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn FormNoValidate(&self) -> bool {
         false
     }
 
-    pub fn SetFormNoValidate(&mut self, _form_no_validate: bool, _rv: &mut ErrorResult) {
+    pub fn SetFormNoValidate(&mut self, _form_no_validate: bool) -> ErrorResult {
+        Ok(())
     }
 
     pub fn FormTarget(&self) -> DOMString {
         None
     }
 
-    pub fn SetFormTarget(&mut self, _form_target: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetFormTarget(&mut self, _form_target: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Height(&self) -> u32 {
         0
     }
 
-    pub fn SetHeight(&mut self, _height: u32, _rv: &mut ErrorResult) {
+    pub fn SetHeight(&mut self, _height: u32) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Indeterminate(&self) -> bool {
@@ -112,112 +124,128 @@ impl HTMLInputElement {
         None
     }
 
-    pub fn SetInputMode(&mut self, _input_mode: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetInputMode(&mut self, _input_mode: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Max(&self) -> DOMString {
         None
     }
 
-    pub fn SetMax(&mut self, _max: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetMax(&mut self, _max: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn MaxLength(&self) -> i32 {
         0
     }
 
-    pub fn SetMaxLength(&mut self, _max_length: i32, _rv: &mut ErrorResult) {
+    pub fn SetMaxLength(&mut self, _max_length: i32) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Min(&self) -> DOMString {
         None
     }
 
-    pub fn SetMin(&mut self, _min: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetMin(&mut self, _min: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Multiple(&self) -> bool {
         false
     }
 
-    pub fn SetMultiple(&mut self, _multiple: bool, _rv: &mut ErrorResult) {
+    pub fn SetMultiple(&mut self, _multiple: bool) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Name(&self) -> DOMString {
         None
     }
 
-    pub fn SetName(&mut self, _name: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetName(&mut self, _name: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Pattern(&self) -> DOMString {
         None
     }
 
-    pub fn SetPattern(&mut self, _pattern: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetPattern(&mut self, _pattern: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Placeholder(&self) -> DOMString {
         None
     }
 
-    pub fn SetPlaceholder(&mut self, _placeholder: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetPlaceholder(&mut self, _placeholder: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn ReadOnly(&self) -> bool {
         false
     }
 
-    pub fn SetReadOnly(&mut self, _read_only: bool, _rv: &mut ErrorResult) {
+    pub fn SetReadOnly(&mut self, _read_only: bool) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Required(&self) -> bool {
         false
     }
 
-    pub fn SetRequired(&mut self, _required: bool, _rv: &mut ErrorResult) {
+    pub fn SetRequired(&mut self, _required: bool) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Size(&self) -> u32 {
         0
     }
 
-    pub fn SetSize(&mut self, _size: u32, _rv: &mut ErrorResult) {
+    pub fn SetSize(&mut self, _size: u32) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Src(&self) -> DOMString {
         None
     }
 
-    pub fn SetSrc(&mut self, _src: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetSrc(&mut self, _src: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Step(&self) -> DOMString {
         None
     }
 
-    pub fn SetStep(&mut self, _step: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetStep(&mut self, _step: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Type(&self) -> DOMString {
         None
     }
 
-    pub fn SetType(&mut self, _type: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetType(&mut self, _type: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn DefaultValue(&self) -> DOMString {
         None
     }
 
-    pub fn SetDefaultValue(&mut self, _default_value: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetDefaultValue(&mut self, _default_value: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Value(&self) -> DOMString {
         None
     }
 
-    pub fn SetValue(&mut self, _value: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetValue(&mut self, _value: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Width(&self) -> u32 {
@@ -234,8 +262,8 @@ impl HTMLInputElement {
     pub fn SetWillValidate(&self, _will_validate: bool) {
     }
 
-    pub fn GetValidationMessage(&self, _rv: &mut ErrorResult) -> DOMString {
-        None
+    pub fn GetValidationMessage(&self) -> Fallible<DOMString> {
+        Ok(None)
     }
 
     pub fn CheckValidity(&self) -> bool {
@@ -248,38 +276,43 @@ impl HTMLInputElement {
     pub fn Select(&self) {
     }
 
-    pub fn GetSelectionStart(&self, _rv: &mut ErrorResult) -> i32 {
-        0
+    pub fn GetSelectionStart(&self) -> Fallible<i32> {
+        Ok(0)
     }
 
-    pub fn SetSelectionStart(&mut self, _selection_start: i32, _rv: &mut ErrorResult) {
+    pub fn SetSelectionStart(&mut self, _selection_start: i32) -> ErrorResult {
+        Ok(())
     }
 
-    pub fn GetSelectionEnd(&self, _rv: &mut ErrorResult) -> i32 {
-        0
+    pub fn GetSelectionEnd(&self) -> Fallible<i32> {
+        Ok(0)
     }
 
-    pub fn SetSelectionEnd(&mut self, _selection_end: i32, _rv: &mut ErrorResult) {
+    pub fn SetSelectionEnd(&mut self, _selection_end: i32) -> ErrorResult {
+        Ok(())
     }
 
-    pub fn GetSelectionDirection(&self, _rv: &mut ErrorResult) -> DOMString {
-        None
+    pub fn GetSelectionDirection(&self) -> Fallible<DOMString> {
+        Ok(None)
     }
 
-    pub fn SetSelectionDirection(&mut self, _selection_direction: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetSelectionDirection(&mut self, _selection_direction: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Align(&self) -> DOMString {
         None
     }
 
-    pub fn SetAlign(&mut self, _align: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetAlign(&mut self, _align: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn UseMap(&self) -> DOMString {
         None
     }
 
-    pub fn SetUseMap(&mut self, _align: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetUseMap(&mut self, _align: &DOMString) -> ErrorResult {
+        Ok(())
     }
 }
diff --git a/src/components/script/dom/htmllegendelement.rs b/src/components/script/dom/htmllegendelement.rs
index 9774c799f0d..96327c3e8cd 100644
--- a/src/components/script/dom/htmllegendelement.rs
+++ b/src/components/script/dom/htmllegendelement.rs
@@ -14,6 +14,7 @@ impl HTMLLegendElement {
         None
     }
 
-    pub fn SetAlign(&mut self, _align: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetAlign(&mut self, _align: &DOMString) -> ErrorResult {
+        Ok(())
     }
 }
diff --git a/src/components/script/dom/htmllielement.rs b/src/components/script/dom/htmllielement.rs
index 58c7ab9618c..1e0966ab4b4 100644
--- a/src/components/script/dom/htmllielement.rs
+++ b/src/components/script/dom/htmllielement.rs
@@ -14,13 +14,15 @@ impl HTMLLIElement {
         0
     }
 
-    pub fn SetValue(&mut self, _value: i32, _rv: &mut ErrorResult) {
+    pub fn SetValue(&mut self, _value: i32) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Type(&self) -> DOMString {
         None
     }
 
-    pub fn SetType(&mut self, _type: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetType(&mut self, _type: &DOMString) -> ErrorResult {
+        Ok(())
     }
 }
diff --git a/src/components/script/dom/htmllinkelement.rs b/src/components/script/dom/htmllinkelement.rs
index f6e2170cec8..9e7f15f9124 100644
--- a/src/components/script/dom/htmllinkelement.rs
+++ b/src/components/script/dom/htmllinkelement.rs
@@ -21,62 +21,71 @@ impl HTMLLinkElement {
         None
     }
 
-    pub fn SetHref(&mut self, _href: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetHref(&mut self, _href: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn CrossOrigin(&self) -> DOMString {
         None
     }
 
-    pub fn SetCrossOrigin(&mut self, _cross_origin: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetCrossOrigin(&mut self, _cross_origin: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Rel(&self) -> DOMString {
         None
     }
 
-    pub fn SetRel(&mut self, _rel: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetRel(&mut self, _rel: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Media(&self) -> DOMString {
         None
     }
 
-    pub fn SetMedia(&mut self, _media: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetMedia(&mut self, _media: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Hreflang(&self) -> DOMString {
         None
     }
 
-    pub fn SetHreflang(&mut self, _href: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetHreflang(&mut self, _href: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Type(&self) -> DOMString {
         None
     }
 
-    pub fn SetType(&mut self, _type: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetType(&mut self, _type: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Charset(&self) -> DOMString {
         None
     }
 
-    pub fn SetCharset(&mut self, _charset: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetCharset(&mut self, _charset: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Rev(&self) -> DOMString {
         None
     }
 
-    pub fn SetRev(&mut self, _rev: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetRev(&mut self, _rev: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Target(&self) -> DOMString {
         None
     }
 
-    pub fn SetTarget(&mut self, _target: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetTarget(&mut self, _target: &DOMString) -> ErrorResult {
+        Ok(())
     }
 }
diff --git a/src/components/script/dom/htmlmapelement.rs b/src/components/script/dom/htmlmapelement.rs
index 71a91dcd2a6..5e130fec014 100644
--- a/src/components/script/dom/htmlmapelement.rs
+++ b/src/components/script/dom/htmlmapelement.rs
@@ -16,7 +16,8 @@ impl HTMLMapElement {
         None
     }
 
-    pub fn SetName(&mut self, _name: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetName(&mut self, _name: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     fn get_scope_and_cx(&self) -> (*JSObject, *JSContext) {
diff --git a/src/components/script/dom/htmlmediaelement.rs b/src/components/script/dom/htmlmediaelement.rs
index 85cfd3b2f77..4a69503c279 100644
--- a/src/components/script/dom/htmlmediaelement.rs
+++ b/src/components/script/dom/htmlmediaelement.rs
@@ -23,7 +23,8 @@ impl HTMLMediaElement {
         None
     }
 
-    pub fn SetSrc(&mut self, _src: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetSrc(&mut self, _src: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn CurrentSrc(&self) -> DOMString {
@@ -34,14 +35,16 @@ impl HTMLMediaElement {
         None
     }
 
-    pub fn SetCrossOrigin(&mut self, _cross_origin: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetCrossOrigin(&mut self, _cross_origin: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Preload(&self) -> DOMString {
         None
     }
 
-    pub fn SetPreload(&mut self, _preload: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetPreload(&mut self, _preload: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Load(&self) {
@@ -63,7 +66,8 @@ impl HTMLMediaElement {
         0f64
     }
 
-    pub fn SetCurrentTime(&mut self, _current_time: f64, _rv: &mut ErrorResult) {
+    pub fn SetCurrentTime(&mut self, _current_time: f64) -> ErrorResult {
+        Ok(())
     }
 
     pub fn GetDuration(&self) -> f64 {
@@ -78,14 +82,16 @@ impl HTMLMediaElement {
         0f64
     }
 
-    pub fn SetDefaultPlaybackRate(&mut self, _default_playback_rate: f64, _rv: &mut ErrorResult) {
+    pub fn SetDefaultPlaybackRate(&mut self, _default_playback_rate: f64) -> ErrorResult {
+        Ok(())
     }
 
     pub fn PlaybackRate(&self) -> f64 {
         0f64
     }
 
-    pub fn SetPlaybackRate(&mut self, _playback_rate: f64, _rv: &mut ErrorResult) {
+    pub fn SetPlaybackRate(&mut self, _playback_rate: f64) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Ended(&self) -> bool {
@@ -96,34 +102,40 @@ impl HTMLMediaElement {
         false
     }
 
-    pub fn SetAutoplay(&mut self, _autoplay: bool, _rv: &mut ErrorResult) {
+    pub fn SetAutoplay(&mut self, _autoplay: bool) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Loop(&self) -> bool {
         false
     }
 
-    pub fn SetLoop(&mut self, _loop: bool, _rv: &mut ErrorResult) {
+    pub fn SetLoop(&mut self, _loop: bool) -> ErrorResult {
+        Ok(())
     }
 
-    pub fn Play(&self, _rv: &mut ErrorResult) {
+    pub fn Play(&self) -> ErrorResult {
+        Ok(())
     }
 
-    pub fn Pause(&self, _rv: &mut ErrorResult) {
+    pub fn Pause(&self) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Controls(&self) -> bool {
         false
     }
 
-    pub fn SetControls(&mut self, _controls: bool, _rv: &mut ErrorResult) {
+    pub fn SetControls(&mut self, _controls: bool) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Volume(&self) -> f64 {
         0f64
     }
 
-    pub fn SetVolume(&mut self, _volume: f64, _rv: &mut ErrorResult) {
+    pub fn SetVolume(&mut self, _volume: f64) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Muted(&self) -> bool {
@@ -137,6 +149,7 @@ impl HTMLMediaElement {
         false
     }
 
-    pub fn SetDefaultMuted(&mut self, _default_muted: bool, _rv: &mut ErrorResult) {
+    pub fn SetDefaultMuted(&mut self, _default_muted: bool) -> ErrorResult {
+        Ok(())
     }
 }
diff --git a/src/components/script/dom/htmlmetaelement.rs b/src/components/script/dom/htmlmetaelement.rs
index d172bab3184..e179af271a4 100644
--- a/src/components/script/dom/htmlmetaelement.rs
+++ b/src/components/script/dom/htmlmetaelement.rs
@@ -14,27 +14,31 @@ impl HTMLMetaElement {
         None
     }
 
-    pub fn SetName(&mut self, _name: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetName(&mut self, _name: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn HttpEquiv(&self) -> DOMString {
         None
     }
 
-    pub fn SetHttpEquiv(&mut self, _http_equiv: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetHttpEquiv(&mut self, _http_equiv: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Content(&self) -> DOMString {
         None
     }
 
-    pub fn SetContent(&mut self, _content: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetContent(&mut self, _content: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Scheme(&self) -> DOMString {
         None
     }
 
-    pub fn SetScheme(&mut self, _scheme: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetScheme(&mut self, _scheme: &DOMString) -> ErrorResult {
+        Ok(())
     }
 }
diff --git a/src/components/script/dom/htmlmeterelement.rs b/src/components/script/dom/htmlmeterelement.rs
index 3a66308adcd..a634e0d1795 100644
--- a/src/components/script/dom/htmlmeterelement.rs
+++ b/src/components/script/dom/htmlmeterelement.rs
@@ -14,41 +14,47 @@ impl HTMLMeterElement {
         0.0
     }
 
-    pub fn SetValue(&mut self, _value: f64, _rv: &mut ErrorResult) {
+    pub fn SetValue(&mut self, _value: f64) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Min(&self) -> f64 {
         0.0
     }
 
-    pub fn SetMin(&mut self, _min: f64, _rv: &mut ErrorResult) {
+    pub fn SetMin(&mut self, _min: f64) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Max(&self) -> f64 {
         0.0
     }
 
-    pub fn SetMax(&mut self, _max: f64, _rv: &mut ErrorResult) {
+    pub fn SetMax(&mut self, _max: f64) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Low(&self) -> f64 {
         0.0
     }
 
-    pub fn SetLow(&mut self, _low: f64, _rv: &mut ErrorResult) {
+    pub fn SetLow(&mut self, _low: f64) -> ErrorResult {
+        Ok(())
     }
 
     pub fn High(&self) -> f64 {
         0.0
     }
 
-    pub fn SetHigh(&mut self, _high: f64, _rv: &mut ErrorResult) {
+    pub fn SetHigh(&mut self, _high: f64) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Optimum(&self) -> f64 {
         0.0
     }
 
-    pub fn SetOptimum(&mut self, _optimum: f64, _rv: &mut ErrorResult) {
+    pub fn SetOptimum(&mut self, _optimum: f64) -> ErrorResult {
+        Ok(())
     }
-}
\ No newline at end of file
+}
diff --git a/src/components/script/dom/htmlmodelement.rs b/src/components/script/dom/htmlmodelement.rs
index 5c046922d83..61ab800b807 100644
--- a/src/components/script/dom/htmlmodelement.rs
+++ b/src/components/script/dom/htmlmodelement.rs
@@ -14,13 +14,15 @@ impl HTMLModElement {
         None
     }
 
-    pub fn SetCite(&mut self, _cite: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetCite(&mut self, _cite: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn DateTime(&self) -> DOMString {
         None
     }
 
-    pub fn SetDateTime(&mut self, _datetime: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetDateTime(&mut self, _datetime: &DOMString) -> ErrorResult {
+        Ok(())
     }
 }
diff --git a/src/components/script/dom/htmlobjectelement.rs b/src/components/script/dom/htmlobjectelement.rs
index 635d2dfa61c..4400649a90f 100644
--- a/src/components/script/dom/htmlobjectelement.rs
+++ b/src/components/script/dom/htmlobjectelement.rs
@@ -18,28 +18,32 @@ impl HTMLObjectElement {
         None
     }
 
-    pub fn SetData(&mut self, _data: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetData(&mut self, _data: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Type(&self) -> DOMString {
         None
     }
 
-    pub fn SetType(&mut self, _type: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetType(&mut self, _type: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Name(&self) -> DOMString {
         None
     }
 
-    pub fn SetName(&mut self, _name: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetName(&mut self, _name: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn UseMap(&self) -> DOMString {
         None
     }
 
-    pub fn SetUseMap(&mut self, _use_map: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetUseMap(&mut self, _use_map: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn GetForm(&self) -> Option<AbstractNode<ScriptView>> {
@@ -50,14 +54,16 @@ impl HTMLObjectElement {
         None
     }
 
-    pub fn SetWidth(&mut self, _width: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetWidth(&mut self, _width: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Height(&self) -> DOMString {
         None
     }
 
-    pub fn SetHeight(&mut self, _height: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetHeight(&mut self, _height: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn GetContentDocument(&self) -> Option<AbstractDocument> {
@@ -91,73 +97,83 @@ impl HTMLObjectElement {
         None
     }
 
-    pub fn SetAlign(&mut self, _align: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetAlign(&mut self, _align: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
-        pub fn Archive(&self) -> DOMString {
+    pub fn Archive(&self) -> DOMString {
         None
     }
 
-    pub fn SetArchive(&mut self, _archive: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetArchive(&mut self, _archive: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Code(&self) -> DOMString {
         None
     }
 
-    pub fn SetCode(&mut self, _code: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetCode(&mut self, _code: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Declare(&self) -> bool {
         false
     }
 
-    pub fn SetDeclare(&mut self, _declare: bool, _rv: &mut ErrorResult) {
+    pub fn SetDeclare(&mut self, _declare: bool) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Hspace(&self) -> u32 {
         0
     }
 
-    pub fn SetHspace(&mut self, _hspace: u32, _rv: &mut ErrorResult) {
+    pub fn SetHspace(&mut self, _hspace: u32) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Standby(&self) -> DOMString {
         None
     }
 
-    pub fn SetStandby(&mut self, _standby: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetStandby(&mut self, _standby: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Vspace(&self) -> u32 {
         0
     }
 
-    pub fn SetVspace(&mut self, _vspace: u32, _rv: &mut ErrorResult) {
+    pub fn SetVspace(&mut self, _vspace: u32) -> ErrorResult {
+        Ok(())
     }
 
     pub fn CodeBase(&self) -> DOMString {
         None
     }
 
-    pub fn SetCodeBase(&mut self, _codebase: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetCodeBase(&mut self, _codebase: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn CodeType(&self) -> DOMString {
         None
     }
 
-    pub fn SetCodeType(&mut self, _codetype: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetCodeType(&mut self, _codetype: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Border(&self) -> DOMString {
         None
     }
 
-    pub fn SetBorder(&mut self, _border: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetBorder(&mut self, _border: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn GetSVGDocument(&self) -> Option<AbstractDocument> {
         None
     }
-}
\ No newline at end of file
+}
diff --git a/src/components/script/dom/htmlolistelement.rs b/src/components/script/dom/htmlolistelement.rs
index a5db8a1d5d5..218b9495768 100644
--- a/src/components/script/dom/htmlolistelement.rs
+++ b/src/components/script/dom/htmlolistelement.rs
@@ -14,27 +14,31 @@ impl HTMLOListElement {
         false
     }
 
-    pub fn SetReversed(&self, _reversed: bool, _rv: &mut ErrorResult) {
+    pub fn SetReversed(&self, _reversed: bool) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Start(&self) -> i32 {
         0
     }
 
-    pub fn SetStart(&mut self, _start: i32, _rv: &mut ErrorResult) {
+    pub fn SetStart(&mut self, _start: i32) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Type(&self) -> DOMString {
         None
     }
 
-    pub fn SetType(&mut self, _type: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetType(&mut self, _type: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Compact(&self) -> bool {
         false
     }
 
-    pub fn SetCompact(&self, _compact: bool, _rv: &mut ErrorResult) {
+    pub fn SetCompact(&self, _compact: bool) -> ErrorResult {
+        Ok(())
     }
-}
\ No newline at end of file
+}
diff --git a/src/components/script/dom/htmloptgroupelement.rs b/src/components/script/dom/htmloptgroupelement.rs
index 99b4d770057..bdd0221ce88 100644
--- a/src/components/script/dom/htmloptgroupelement.rs
+++ b/src/components/script/dom/htmloptgroupelement.rs
@@ -14,13 +14,15 @@ impl HTMLOptGroupElement {
         false
     }
 
-    pub fn SetDisabled(&mut self, _disabled: bool, _rv: &mut ErrorResult) {
+    pub fn SetDisabled(&mut self, _disabled: bool) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Label(&self) -> DOMString {
         None
     }
 
-    pub fn SetLabel(&mut self, _label: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetLabel(&mut self, _label: &DOMString) -> ErrorResult {
+        Ok(())
     }
 }
diff --git a/src/components/script/dom/htmloptionelement.rs b/src/components/script/dom/htmloptionelement.rs
index 90144fe1eb0..0aa1b07a3ad 100644
--- a/src/components/script/dom/htmloptionelement.rs
+++ b/src/components/script/dom/htmloptionelement.rs
@@ -15,7 +15,8 @@ impl HTMLOptionElement {
         false
     }
 
-    pub fn SetDisabled(&mut self, _disabled: bool, _rv: &mut ErrorResult) {
+    pub fn SetDisabled(&mut self, _disabled: bool) -> ErrorResult {
+        Ok(())
     }
 
     pub fn GetForm(&self) -> Option<AbstractNode<ScriptView>> {
@@ -26,38 +27,43 @@ impl HTMLOptionElement {
         None
     }
 
-    pub fn SetLabel(&mut self, _label: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetLabel(&mut self, _label: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn DefaultSelected(&self) -> bool {
         false
     }
 
-    pub fn SetDefaultSelected(&mut self, _default_selected: bool, _rv: &mut ErrorResult) {
+    pub fn SetDefaultSelected(&mut self, _default_selected: bool) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Selected(&self) -> bool {
         false
     }
 
-    pub fn SetSelected(&mut self, _selected: bool, _rv: &mut ErrorResult) {
+    pub fn SetSelected(&mut self, _selected: bool) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Value(&self) -> DOMString {
         None
     }
 
-    pub fn SetValue(&mut self, _value: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetValue(&mut self, _value: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Text(&self) -> DOMString {
         None
     }
 
-    pub fn SetText(&mut self, _text: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetText(&mut self, _text: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Index(&self) -> i32 {
         0
     }
-}
\ No newline at end of file
+}
diff --git a/src/components/script/dom/htmloutputelement.rs b/src/components/script/dom/htmloutputelement.rs
index 47a43f75cc3..d6843644e1f 100644
--- a/src/components/script/dom/htmloutputelement.rs
+++ b/src/components/script/dom/htmloutputelement.rs
@@ -20,7 +20,8 @@ impl HTMLOutputElement {
         None
     }
 
-    pub fn SetName(&mut self, _name: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetName(&mut self, _name: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Type(&self) -> DOMString {
@@ -31,14 +32,16 @@ impl HTMLOutputElement {
         None
     }
 
-    pub fn SetDefaultValue(&mut self, _value: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetDefaultValue(&mut self, _value: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Value(&self) -> DOMString {
         None
     }
 
-    pub fn SetValue(&mut self, _value: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetValue(&mut self, _value: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn WillValidate(&self) -> bool {
@@ -59,7 +62,8 @@ impl HTMLOutputElement {
         None
     }
 
-    pub fn SetValidationMessage(&mut self, _message: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetValidationMessage(&mut self, _message: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn CheckValidity(&self) -> bool {
diff --git a/src/components/script/dom/htmlparagraphelement.rs b/src/components/script/dom/htmlparagraphelement.rs
index d09b4d6bc0a..ff0a4c51155 100644
--- a/src/components/script/dom/htmlparagraphelement.rs
+++ b/src/components/script/dom/htmlparagraphelement.rs
@@ -14,6 +14,7 @@ impl HTMLParagraphElement {
         None
     }
 
-    pub fn SetAlign(&mut self, _align: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetAlign(&mut self, _align: &DOMString) -> ErrorResult {
+        Ok(())
     }
 }
diff --git a/src/components/script/dom/htmlparamelement.rs b/src/components/script/dom/htmlparamelement.rs
index 90409046f98..e3ba463a242 100644
--- a/src/components/script/dom/htmlparamelement.rs
+++ b/src/components/script/dom/htmlparamelement.rs
@@ -14,27 +14,31 @@ impl HTMLParamElement {
         None
     }
 
-    pub fn SetName(&mut self, _name: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetName(&mut self, _name: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Value(&self) -> DOMString {
         None
     }
 
-    pub fn SetValue(&mut self, _value: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetValue(&mut self, _value: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Type(&self) -> DOMString {
         None
     }
 
-    pub fn SetType(&mut self, _type: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetType(&mut self, _type: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn ValueType(&self) -> DOMString {
         None
     }
 
-    pub fn SetValueType(&mut self, _value_type: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetValueType(&mut self, _value_type: &DOMString) -> ErrorResult {
+        Ok(())
     }
-}
\ No newline at end of file
+}
diff --git a/src/components/script/dom/htmlpreelement.rs b/src/components/script/dom/htmlpreelement.rs
index ebdf6224273..4e5ddb49fa6 100644
--- a/src/components/script/dom/htmlpreelement.rs
+++ b/src/components/script/dom/htmlpreelement.rs
@@ -14,6 +14,7 @@ impl HTMLPreElement {
         0
     }
 
-    pub fn SetWidth(&mut self, _width: i32, _rv: &mut ErrorResult) {
+    pub fn SetWidth(&mut self, _width: i32) -> ErrorResult {
+        Ok(())
     }
 }
diff --git a/src/components/script/dom/htmlprogresselement.rs b/src/components/script/dom/htmlprogresselement.rs
index b4aebf5c8cd..982be3daf91 100644
--- a/src/components/script/dom/htmlprogresselement.rs
+++ b/src/components/script/dom/htmlprogresselement.rs
@@ -2,7 +2,7 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-use dom::bindings::utils::{ErrorResult};
+use dom::bindings::utils::{ErrorResult, Fallible};
 use dom::htmlelement::HTMLElement;
 
 pub struct HTMLProgressElement {
@@ -14,21 +14,23 @@ impl HTMLProgressElement {
         0f64
     }
 
-    pub fn SetValue(&mut self, _value: f64, _rv: &mut ErrorResult) {
+    pub fn SetValue(&mut self, _value: f64) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Max(&self) -> f64 {
         0f64
     }
 
-    pub fn SetMax(&mut self, _max: f64, _rv: &mut ErrorResult) {
+    pub fn SetMax(&mut self, _max: f64) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Position(&self) -> f64 {
         0f64
     }
 
-    pub fn GetPositiom(&self, _rv: &mut ErrorResult) -> f64 {
-        0f64
+    pub fn GetPositiom(&self) -> Fallible<f64> {
+        Ok(0f64)
     }
 }
diff --git a/src/components/script/dom/htmlquoteelement.rs b/src/components/script/dom/htmlquoteelement.rs
index fd82fa9351f..378078a85f3 100644
--- a/src/components/script/dom/htmlquoteelement.rs
+++ b/src/components/script/dom/htmlquoteelement.rs
@@ -14,6 +14,7 @@ impl HTMLQuoteElement {
         None
     }
 
-    pub fn SetCite(&self, _cite: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetCite(&self, _cite: &DOMString) -> ErrorResult {
+        Ok(())
     }
 }
diff --git a/src/components/script/dom/htmlscriptelement.rs b/src/components/script/dom/htmlscriptelement.rs
index 18d28967893..ca6debddb34 100644
--- a/src/components/script/dom/htmlscriptelement.rs
+++ b/src/components/script/dom/htmlscriptelement.rs
@@ -14,62 +14,71 @@ impl HTMLScriptElement {
         None
     }
 
-    pub fn SetSrc(&mut self, _src: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetSrc(&mut self, _src: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Type(&self) -> DOMString {
         None
     }
 
-    pub fn SetType(&mut self, _type: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetType(&mut self, _type: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Charset(&self) -> DOMString {
         None
     }
 
-    pub fn SetCharset(&mut self, _charset: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetCharset(&mut self, _charset: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Async(&self) -> bool {
         false
     }
 
-    pub fn SetAsync(&self, _async: bool, _rv: &mut ErrorResult) {
+    pub fn SetAsync(&self, _async: bool) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Defer(&self) -> bool {
         false
     }
 
-    pub fn SetDefer(&self, _defer: bool, _rv: &mut ErrorResult) {
+    pub fn SetDefer(&self, _defer: bool) -> ErrorResult {
+        Ok(())
     }
 
     pub fn CrossOrigin(&self) -> DOMString {
         None
     }
 
-    pub fn SetCrossOrigin(&mut self, _cross_origin: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetCrossOrigin(&mut self, _cross_origin: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Text(&self) -> DOMString {
         None
     }
 
-    pub fn SetText(&mut self, _text: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetText(&mut self, _text: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Event(&self) -> DOMString {
         None
     }
 
-    pub fn SetEvent(&mut self, _event: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetEvent(&mut self, _event: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn HtmlFor(&self) -> DOMString {
         None
     }
 
-    pub fn SetHtmlFor(&mut self, _html_for: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetHtmlFor(&mut self, _html_for: &DOMString) -> ErrorResult {
+        Ok(())
     }
 }
diff --git a/src/components/script/dom/htmlselectelement.rs b/src/components/script/dom/htmlselectelement.rs
index 2db41902bef..b6c7f248d20 100644
--- a/src/components/script/dom/htmlselectelement.rs
+++ b/src/components/script/dom/htmlselectelement.rs
@@ -16,14 +16,16 @@ impl HTMLSelectElement {
         false
     }
 
-    pub fn SetAutofocus(&mut self, _autofocus: bool, _rv: &mut ErrorResult) {
+    pub fn SetAutofocus(&mut self, _autofocus: bool) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Disabled(&self) -> bool {
         false
     }
 
-    pub fn SetDisabled(&mut self, _disabled: bool, _rv: &mut ErrorResult) {
+    pub fn SetDisabled(&mut self, _disabled: bool) -> ErrorResult {
+        Ok(())
     }
 
     pub fn GetForm(&self) -> Option<AbstractNode<ScriptView>> {
@@ -34,28 +36,32 @@ impl HTMLSelectElement {
         false
     }
 
-    pub fn SetMultiple(&mut self, _multiple: bool, _rv: &mut ErrorResult) {
+    pub fn SetMultiple(&mut self, _multiple: bool) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Name(&self) -> DOMString {
         None
     }
 
-    pub fn SetName(&mut self, _name: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetName(&mut self, _name: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Required(&self) -> bool {
         false
     }
 
-    pub fn SetRequired(&mut self, _multiple: bool, _rv: &mut ErrorResult) {
+    pub fn SetRequired(&mut self, _multiple: bool) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Size(&self) -> u32 {
         0
     }
 
-    pub fn SetSize(&mut self, _size: u32, _rv: &mut ErrorResult) {
+    pub fn SetSize(&mut self, _size: u32) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Type(&self) -> DOMString {
@@ -66,7 +72,8 @@ impl HTMLSelectElement {
         0
     }
 
-    pub fn SetLength(&mut self, _length: u32, _rv: &mut ErrorResult) {
+    pub fn SetLength(&mut self, _length: u32) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Item(&self, _index: u32) -> Option<AbstractNode<ScriptView>> {
@@ -81,7 +88,8 @@ impl HTMLSelectElement {
         None
     }
 
-    pub fn IndexedSetter(&mut self, _index: u32, _option: Option<AbstractNode<ScriptView>>, _rv: &mut ErrorResult) {
+    pub fn IndexedSetter(&mut self, _index: u32, _option: Option<AbstractNode<ScriptView>>) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Remove_(&self) {
@@ -94,7 +102,8 @@ impl HTMLSelectElement {
         0
     }
 
-    pub fn SetSelectedIndex(&mut self, _index: i32, _rv: &mut ErrorResult) {
+    pub fn SetSelectedIndex(&mut self, _index: i32) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Value(&self) -> DOMString {
@@ -122,7 +131,8 @@ impl HTMLSelectElement {
         None
     }
 
-    pub fn SetValidationMessage(&mut self, _message: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetValidationMessage(&mut self, _message: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn CheckValidity(&self) -> bool {
@@ -131,4 +141,4 @@ impl HTMLSelectElement {
 
     pub fn SetCustomValidity(&mut self, _error: &DOMString) {
     }
-}
\ No newline at end of file
+}
diff --git a/src/components/script/dom/htmlsourceelement.rs b/src/components/script/dom/htmlsourceelement.rs
index ad2549e0dc3..b48a42f0589 100644
--- a/src/components/script/dom/htmlsourceelement.rs
+++ b/src/components/script/dom/htmlsourceelement.rs
@@ -14,20 +14,23 @@ impl HTMLSourceElement {
         None
     }
     
-    pub fn SetSrc(&mut self, _src: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetSrc(&mut self, _src: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Type(&self) -> DOMString {
         None
     }
     
-    pub fn SetType(&mut self, _type: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetType(&mut self, _type: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Media(&self) -> DOMString {
         None
     }
     
-    pub fn SetMedia(&mut self, _media: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetMedia(&mut self, _media: &DOMString) -> ErrorResult {
+        Ok(())
     }
 }
diff --git a/src/components/script/dom/htmlstyleelement.rs b/src/components/script/dom/htmlstyleelement.rs
index 1384f8b5dcc..341fe69b2c1 100644
--- a/src/components/script/dom/htmlstyleelement.rs
+++ b/src/components/script/dom/htmlstyleelement.rs
@@ -21,20 +21,23 @@ impl HTMLStyleElement {
         None
     }
 
-    pub fn SetMedia(&mut self, _media: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetMedia(&mut self, _media: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Type(&self) -> DOMString {
         None
     }
 
-    pub fn SetType(&mut self, _type: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetType(&mut self, _type: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Scoped(&self) -> bool {
         false
     }
 
-    pub fn SetScoped(&self, _scoped: bool, _rv: &mut ErrorResult) {
+    pub fn SetScoped(&self, _scoped: bool) -> ErrorResult {
+        Ok(())
     }
 }
diff --git a/src/components/script/dom/htmltablecaptionelement.rs b/src/components/script/dom/htmltablecaptionelement.rs
index ed114eefe9a..3e2eb2a32e8 100644
--- a/src/components/script/dom/htmltablecaptionelement.rs
+++ b/src/components/script/dom/htmltablecaptionelement.rs
@@ -14,6 +14,7 @@ impl HTMLTableCaptionElement {
         None
     }
     
-    pub fn SetAlign(&mut self, _align: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetAlign(&mut self, _align: &DOMString) -> ErrorResult {
+        Ok(())
     }
 }
diff --git a/src/components/script/dom/htmltablecellelement.rs b/src/components/script/dom/htmltablecellelement.rs
index a65411b39d3..507453cd280 100644
--- a/src/components/script/dom/htmltablecellelement.rs
+++ b/src/components/script/dom/htmltablecellelement.rs
@@ -14,104 +14,119 @@ impl HTMLTableCellElement {
         0
     }
 
-    pub fn SetColSpan(&self, _col_span: u32, _rv: &mut ErrorResult) {
+    pub fn SetColSpan(&self, _col_span: u32) -> ErrorResult {
+        Ok(())
     }
 
     pub fn RowSpan(&self) -> u32 {
         0
     }
 
-    pub fn SetRowSpan(&self, _col_span: u32, _rv: &mut ErrorResult) {
+    pub fn SetRowSpan(&self, _col_span: u32) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Headers(&self) -> DOMString {
         None
     }
 
-    pub fn SetHeaders(&self, _headers: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetHeaders(&self, _headers: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn CellIndex(&self) -> i32 {
         0
     }
 
-    pub fn GetCellIndex(&self, _cell_index: i32, _rv: &mut ErrorResult) {
+    pub fn GetCellIndex(&self, _cell_index: i32) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Abbr(&self) -> DOMString {
         None
     }
 
-    pub fn SetAbbr(&self, _abbr: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetAbbr(&self, _abbr: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Scope(&self) -> DOMString {
         None
     }
 
-    pub fn SetScope(&self, _abbr: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetScope(&self, _abbr: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Align(&self) -> DOMString {
         None
     }
 
-    pub fn SetAlign(&self, _align: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetAlign(&self, _align: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Axis(&self) -> DOMString {
         None
     }
 
-    pub fn SetAxis(&self, _axis: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetAxis(&self, _axis: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Height(&self) -> DOMString {
         None
     }
 
-    pub fn SetHeight(&self, _height: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetHeight(&self, _height: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Width(&self) -> DOMString {
         None
     }
 
-    pub fn SetWidth(&self, _width: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetWidth(&self, _width: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Ch(&self) -> DOMString {
         None
     }
 
-    pub fn SetCh(&self, _ch: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetCh(&self, _ch: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn ChOff(&self) -> DOMString {
         None
     }
 
-    pub fn SetChOff(&self, _ch_off: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetChOff(&self, _ch_off: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn NoWrap(&self) -> bool {
         false
     }
 
-    pub fn SetNoWrap(&self, _no_wrap: bool, _rv: &mut ErrorResult) {
+    pub fn SetNoWrap(&self, _no_wrap: bool) -> ErrorResult {
+        Ok(())
     }
 
     pub fn VAlign(&self) -> DOMString {
         None
     }
 
-    pub fn SetVAlign(&self, _valign: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetVAlign(&self, _valign: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn BgColor(&self) -> DOMString {
         None
     }
 
-    pub fn SetBgColor(&self, _bg_color: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetBgColor(&self, _bg_color: &DOMString) -> ErrorResult {
+        Ok(())
     }
 }
diff --git a/src/components/script/dom/htmltablecolelement.rs b/src/components/script/dom/htmltablecolelement.rs
index 64670c51f98..68c931aaa78 100644
--- a/src/components/script/dom/htmltablecolelement.rs
+++ b/src/components/script/dom/htmltablecolelement.rs
@@ -14,41 +14,47 @@ impl HTMLTableColElement {
         0
     }
 
-    pub fn SetSpan(&mut self, _span: u32, _rv: &mut ErrorResult) {
+    pub fn SetSpan(&mut self, _span: u32) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Align(&self) -> DOMString {
         None
     }
 
-    pub fn SetAlign(&mut self, _align: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetAlign(&mut self, _align: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Ch(&self) -> DOMString {
         None
     }
 
-    pub fn SetCh(&mut self, _ch: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetCh(&mut self, _ch: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn ChOff(&self) -> DOMString {
         None
     }
 
-    pub fn SetChOff(&mut self, _ch_off: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetChOff(&mut self, _ch_off: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn VAlign(&self) -> DOMString {
         None
     }
 
-    pub fn SetVAlign(&mut self, _v_align: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetVAlign(&mut self, _v_align: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Width(&self) -> DOMString {
         None
     }
 
-    pub fn SetWidth(&mut self, _width: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetWidth(&mut self, _width: &DOMString) -> ErrorResult {
+        Ok(())
     }
 }
diff --git a/src/components/script/dom/htmltableelement.rs b/src/components/script/dom/htmltableelement.rs
index 5e322edb02d..d098b7f070c 100644
--- a/src/components/script/dom/htmltableelement.rs
+++ b/src/components/script/dom/htmltableelement.rs
@@ -20,7 +20,8 @@ impl HTMLTableElement {
     pub fn DeleteTFoot(&self) {
     }
 
-    pub fn DeleteRow(&mut self, _index: i32, _rv: &mut ErrorResult) {
+    pub fn DeleteRow(&mut self, _index: i32) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Sortable(&self) -> bool {
@@ -37,62 +38,71 @@ impl HTMLTableElement {
         None
     }
 
-    pub fn SetAlign(&self, _align: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetAlign(&self, _align: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Border(&self) -> DOMString {
         None
     }
 
-    pub fn SetBorder(&self, _border: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetBorder(&self, _border: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Frame(&self) -> DOMString {
         None
     }
 
-    pub fn SetFrame(&self, _frame: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetFrame(&self, _frame: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Rules(&self) -> DOMString {
         None
     }
 
-    pub fn SetRules(&self, _rules: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetRules(&self, _rules: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Summary(&self) -> DOMString {
         None
     }
 
-    pub fn SetSummary(&self, _summary: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetSummary(&self, _summary: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Width(&self) -> DOMString {
         None
     }
 
-    pub fn SetWidth(&self, _width: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetWidth(&self, _width: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn BgColor(&self) -> DOMString {
         None
     }
 
-    pub fn SetBgColor(&self, _bg_color: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetBgColor(&self, _bg_color: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn CellPadding(&self) -> DOMString {
         None
     }
 
-    pub fn SetCellPadding(&self, _cell_padding: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetCellPadding(&self, _cell_padding: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn CellSpacing(&self) -> DOMString {
         None
     }
 
-    pub fn SetCellSpacing(&self, _cell_spacing: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetCellSpacing(&self, _cell_spacing: &DOMString) -> ErrorResult {
+        Ok(())
     }
 }
diff --git a/src/components/script/dom/htmltablerowelement.rs b/src/components/script/dom/htmltablerowelement.rs
index 3833d389475..f1ab0a33a3b 100644
--- a/src/components/script/dom/htmltablerowelement.rs
+++ b/src/components/script/dom/htmltablerowelement.rs
@@ -26,41 +26,47 @@ impl HTMLTableRowElement {
         0
     }
 
-    pub fn DeleteCell(&mut self, _index: i32, _rv: &mut ErrorResult) {
+    pub fn DeleteCell(&mut self, _index: i32) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Align(&self) -> DOMString {
         None
     }
 
-    pub fn SetAlign(&self, _align: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetAlign(&self, _align: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Ch(&self) -> DOMString {
         None
     }
 
-    pub fn SetCh(&self, _ch: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetCh(&self, _ch: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn ChOff(&self) -> DOMString {
         None
     }
 
-    pub fn SetChOff(&self, _ch_off: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetChOff(&self, _ch_off: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn VAlign(&self) -> DOMString {
         None
     }
 
-    pub fn SetVAlign(&self, _v_align: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetVAlign(&self, _v_align: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn BgColor(&self) -> DOMString {
         None
     }
 
-    pub fn SetBgColor(&self, _bg_color: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetBgColor(&self, _bg_color: &DOMString) -> ErrorResult {
+        Ok(())
     }
 }
diff --git a/src/components/script/dom/htmltablesectionelement.rs b/src/components/script/dom/htmltablesectionelement.rs
index 2fc93212068..d42f4cb514a 100644
--- a/src/components/script/dom/htmltablesectionelement.rs
+++ b/src/components/script/dom/htmltablesectionelement.rs
@@ -10,34 +10,39 @@ pub struct HTMLTableSectionElement {
 }
 
 impl HTMLTableSectionElement {
-    pub fn DeleteRow(&mut self, _index: i32, _rv: &mut ErrorResult) {
+    pub fn DeleteRow(&mut self, _index: i32) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Align(&self) -> DOMString {
         None
     }
 
-    pub fn SetAlign(&mut self, _align: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetAlign(&mut self, _align: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Ch(&self) -> DOMString {
         None
     }
 
-    pub fn SetCh(&mut self, _ch: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetCh(&mut self, _ch: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn ChOff(&self) -> DOMString {
         None
     }
 
-    pub fn SetChOff(&mut self, _ch_off: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetChOff(&mut self, _ch_off: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn VAlign(&self) -> DOMString {
         None
     }
 
-    pub fn SetVAlign(&mut self, _v_align: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetVAlign(&mut self, _v_align: &DOMString) -> ErrorResult {
+        Ok(())
     }
 }
diff --git a/src/components/script/dom/htmltextareaelement.rs b/src/components/script/dom/htmltextareaelement.rs
index 301fd2af44d..377609797de 100644
--- a/src/components/script/dom/htmltextareaelement.rs
+++ b/src/components/script/dom/htmltextareaelement.rs
@@ -2,7 +2,7 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-use dom::bindings::utils::{DOMString, ErrorResult};
+use dom::bindings::utils::{DOMString, ErrorResult, Fallible};
 use dom::htmlelement::HTMLElement;
 
 pub struct HTMLTextAreaElement {
@@ -14,70 +14,80 @@ impl HTMLTextAreaElement {
         false
     }
 
-    pub fn SetAutofocus(&mut self, _autofocus: bool, _rv: &mut ErrorResult) {
+    pub fn SetAutofocus(&mut self, _autofocus: bool) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Cols(&self) -> u32 {
         0
     }
 
-    pub fn SetCols(&self, _cols: u32, _rv: &mut ErrorResult) {
+    pub fn SetCols(&self, _cols: u32) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Disabled(&self) -> bool {
         false
     }
 
-    pub fn SetDisabled(&mut self, _disabled: bool, _rv: &mut ErrorResult) {
+    pub fn SetDisabled(&mut self, _disabled: bool) -> ErrorResult {
+        Ok(())
     }
 
     pub fn MaxLength(&self) -> i32 {
         0
     }
 
-    pub fn SetMaxLength(&self, _max_length: i32, _rv: &mut ErrorResult) {
+    pub fn SetMaxLength(&self, _max_length: i32) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Name(&self) -> DOMString {
         None
     }
 
-    pub fn SetName(&mut self, _name: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetName(&mut self, _name: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Placeholder(&self) -> DOMString {
         None
     }
 
-    pub fn SetPlaceholder(&mut self, _placeholder: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetPlaceholder(&mut self, _placeholder: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn ReadOnly(&self) -> bool {
         false
     }
 
-    pub fn SetReadOnly(&mut self, _read_only: bool, _rv: &mut ErrorResult) {
+    pub fn SetReadOnly(&mut self, _read_only: bool) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Required(&self) -> bool {
         false
     }
 
-    pub fn SetRequired(&mut self, _required: bool, _rv: &mut ErrorResult) {
+    pub fn SetRequired(&mut self, _required: bool) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Rows(&self) -> u32 {
         0
     }
 
-    pub fn SetRows(&self, _rows: u32, _rv: &mut ErrorResult) {
+    pub fn SetRows(&self, _rows: u32) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Wrap(&self) -> DOMString {
         None
     }
 
-    pub fn SetWrap(&mut self, _wrap: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetWrap(&mut self, _wrap: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Type(&self) -> DOMString {
@@ -91,7 +101,8 @@ impl HTMLTextAreaElement {
         None
     }
 
-    pub fn SetDefaultValue(&mut self, _default_value: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetDefaultValue(&mut self, _default_value: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Value(&self) -> DOMString {
@@ -105,14 +116,16 @@ impl HTMLTextAreaElement {
         0
     }
 
-    pub fn SetTextLength(&self, _text_length: u32, _rv: &mut ErrorResult) {
+    pub fn SetTextLength(&self, _text_length: u32) -> ErrorResult {
+        Ok(())
     }
 
     pub fn WillValidate(&self) -> bool {
         false
     }
 
-    pub fn SetWillValidate(&mut self, _will_validate: bool, _rv: &mut ErrorResult) {
+    pub fn SetWillValidate(&mut self, _will_validate: bool) -> ErrorResult {
+        Ok(())
     }
 
     pub fn ValidationMessage(&self) -> DOMString {
@@ -129,25 +142,28 @@ impl HTMLTextAreaElement {
     pub fn Select(&self) {
     }
 
-    pub fn GetSelectionStart(&self, _rv: &mut ErrorResult) -> u32 {
-        0
+    pub fn GetSelectionStart(&self) -> Fallible<u32> {
+        Ok(0)
     }
 
-    pub fn SetSelectionStart(&self, _selection_start: u32, _rv: &mut ErrorResult) {
+    pub fn SetSelectionStart(&self, _selection_start: u32) -> ErrorResult {
+        Ok(())
     }
 
-    pub fn GetSelectionEnd(&self, _rv: &mut ErrorResult) -> u32 {
-        0
+    pub fn GetSelectionEnd(&self) -> Fallible<u32> {
+        Ok(0)
     }
 
-    pub fn SetSelectionEnd(&self, _selection_end: u32, _rv: &mut ErrorResult) {
+    pub fn SetSelectionEnd(&self, _selection_end: u32) -> ErrorResult {
+        Ok(())
     }
 
-    pub fn GetSelectionDirection(&self, _rv: &mut ErrorResult) -> DOMString {
-        None
+    pub fn GetSelectionDirection(&self) -> Fallible<DOMString> {
+        Ok(None)
     }
 
-    pub fn SetSelectionDirection(&self, _selection_direction: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetSelectionDirection(&self, _selection_direction: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn SetRangeText(&self, _replacement: &DOMString) {
diff --git a/src/components/script/dom/htmltimeelement.rs b/src/components/script/dom/htmltimeelement.rs
index 0e0320a3bf1..82b535e66c4 100644
--- a/src/components/script/dom/htmltimeelement.rs
+++ b/src/components/script/dom/htmltimeelement.rs
@@ -14,6 +14,7 @@ impl HTMLTimeElement {
         None
     }
     
-    pub fn SetDateTime(&mut self, _dateTime: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetDateTime(&mut self, _dateTime: &DOMString) -> ErrorResult {
+        Ok(())
     }
 }
diff --git a/src/components/script/dom/htmltitleelement.rs b/src/components/script/dom/htmltitleelement.rs
index 76adcc1f8f4..829c8c86be7 100644
--- a/src/components/script/dom/htmltitleelement.rs
+++ b/src/components/script/dom/htmltitleelement.rs
@@ -14,6 +14,7 @@ impl HTMLTitleElement {
         None
     }
 
-    pub fn SetText(&mut self, _text: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetText(&mut self, _text: &DOMString) -> ErrorResult {
+        Ok(())
     }
 }
diff --git a/src/components/script/dom/htmltrackelement.rs b/src/components/script/dom/htmltrackelement.rs
index 4a7ff5b71cb..0148b01cb81 100644
--- a/src/components/script/dom/htmltrackelement.rs
+++ b/src/components/script/dom/htmltrackelement.rs
@@ -14,35 +14,40 @@ impl HTMLTrackElement {
         None
     }
 
-    pub fn SetKind(&mut self, _kind: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetKind(&mut self, _kind: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Src(&self) -> DOMString {
         None
     }
 
-    pub fn SetSrc(&mut self, _src: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetSrc(&mut self, _src: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Srclang(&self) -> DOMString {
         None
     }
 
-    pub fn SetSrclang(&mut self, _srclang: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetSrclang(&mut self, _srclang: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Label(&self) -> DOMString {
         None
     }
 
-    pub fn SetLabel(&mut self, _label: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetLabel(&mut self, _label: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Default(&self) -> bool {
         false
     }
 
-    pub fn SetDefault(&mut self, _default: bool, _rv: &mut ErrorResult) {
+    pub fn SetDefault(&mut self, _default: bool) -> ErrorResult {
+        Ok(())
     }
 
     pub fn ReadyState(&self) -> u16 {
diff --git a/src/components/script/dom/htmlulistelement.rs b/src/components/script/dom/htmlulistelement.rs
index a85e178af77..1135ba98bcb 100644
--- a/src/components/script/dom/htmlulistelement.rs
+++ b/src/components/script/dom/htmlulistelement.rs
@@ -14,13 +14,15 @@ impl HTMLUListElement {
         false
     }
     
-    pub fn SetCompact(&mut self, _compact: bool, _rv: &mut ErrorResult) {
+    pub fn SetCompact(&mut self, _compact: bool) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Type(&self) -> DOMString {
         None
     }
 
-    pub fn SetType(&mut self, _type: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetType(&mut self, _type: &DOMString) -> ErrorResult {
+        Ok(())
     }
 }
diff --git a/src/components/script/dom/htmlvideoelement.rs b/src/components/script/dom/htmlvideoelement.rs
index 68f34b28665..59d819b2ba4 100644
--- a/src/components/script/dom/htmlvideoelement.rs
+++ b/src/components/script/dom/htmlvideoelement.rs
@@ -14,14 +14,16 @@ impl HTMLVideoElement {
         0
     }
 
-    pub fn SetWidth(&mut self, _width: u32, _rv: &ErrorResult) {
+    pub fn SetWidth(&mut self, _width: u32) -> ErrorResult {
+        Ok(())
     }
 
     pub fn Height(&self) -> u32 {
         0
     }
 
-    pub fn SetHeight(&mut self, _height: u32, _rv: &ErrorResult) {
+    pub fn SetHeight(&mut self, _height: u32) -> ErrorResult {
+        Ok(())
     }
 
     pub fn VideoWidth(&self) -> u32 {
@@ -36,6 +38,7 @@ impl HTMLVideoElement {
         None
     }
 
-    pub fn SetPoster(&mut self, _poster: &DOMString, _rv: &ErrorResult) {
+    pub fn SetPoster(&mut self, _poster: &DOMString) -> ErrorResult {
+        Ok(())
     }
 }
diff --git a/src/components/script/dom/mouseevent.rs b/src/components/script/dom/mouseevent.rs
index fe986d581a0..6a455279840 100644
--- a/src/components/script/dom/mouseevent.rs
+++ b/src/components/script/dom/mouseevent.rs
@@ -3,7 +3,7 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 use dom::bindings::codegen::MouseEventBinding;
-use dom::bindings::utils::{ErrorResult, DOMString};
+use dom::bindings::utils::{ErrorResult, Fallible, DOMString};
 use dom::bindings::utils::{CacheableWrapper, WrapperCache, BindingObject, DerivedWrapper};
 use dom::eventtarget::EventTarget;
 use dom::uievent::UIEvent;
@@ -54,12 +54,11 @@ impl MouseEvent {
 
     pub fn Constructor(_owner: @mut Window,
                        type_: &DOMString,
-                       init: &MouseEventBinding::MouseEventInit,
-                       _rv: &mut ErrorResult) -> @mut MouseEvent {
-        @mut MouseEvent::new(type_, init.bubbles, init.cancelable, init.view, init.detail,
-                             init.screenX, init.screenY, init.clientX, init.clientY,
-                             init.ctrlKey, init.shiftKey, init.altKey, init.metaKey,
-                             init.button, init.buttons, init.relatedTarget)
+                       init: &MouseEventBinding::MouseEventInit) -> Fallible<@mut MouseEvent> {
+        Ok(@mut MouseEvent::new(type_, init.bubbles, init.cancelable, init.view, init.detail,
+                                init.screenX, init.screenY, init.clientX, init.clientY,
+                                init.ctrlKey, init.shiftKey, init.altKey, init.metaKey,
+                                init.button, init.buttons, init.relatedTarget))
     }
 
     pub fn ScreenX(&self) -> i32 {
@@ -127,8 +126,7 @@ impl MouseEvent {
                           shiftKeyArg: bool,
                           metaKeyArg: bool,
                           buttonArg: u16,
-                          relatedTargetArg: Option<@mut EventTarget>,
-                          _rv: &mut ErrorResult) {
+                          relatedTargetArg: Option<@mut EventTarget>) -> ErrorResult {
         self.parent.InitUIEvent(typeArg, canBubbleArg, cancelableArg, viewArg, detailArg);
         self.screen_x = screenXArg;
         self.screen_y = screenYArg;
@@ -140,6 +138,7 @@ impl MouseEvent {
         self.meta_key = metaKeyArg;
         self.button = buttonArg;
         self.related_target = relatedTargetArg;
+        Ok(())
     }
 }
 
diff --git a/src/components/script/dom/navigator.rs b/src/components/script/dom/navigator.rs
index cab048ff30b..144f5a548b5 100644
--- a/src/components/script/dom/navigator.rs
+++ b/src/components/script/dom/navigator.rs
@@ -3,7 +3,7 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 use dom::bindings::utils::{WrapperCache, BindingObject, CacheableWrapper};
-use dom::bindings::utils::{DOMString, ErrorResult};
+use dom::bindings::utils::{DOMString, Fallible};
 use dom::bindings::codegen::NavigatorBinding;
 use script_task::{page_from_context};
 
@@ -46,12 +46,12 @@ impl Navigator {
         false
     }
 
-    pub fn GetBuildID(&self, _rv: &mut ErrorResult) -> DOMString {
-        None
+    pub fn GetBuildID(&self) -> Fallible<DOMString> {
+        Ok(None)
     }
 
-    pub fn JavaEnabled(&self, _rv: &mut ErrorResult) -> bool {
-        false
+    pub fn JavaEnabled(&self) -> Fallible<bool> {
+        Ok(false)
     }
 
     pub fn TaintEnabled(&self) -> bool {
@@ -62,20 +62,20 @@ impl Navigator {
         Some(~"Netscape") // Like Gecko/Webkit
     }
 
-    pub fn GetAppCodeName(&self, _rv: &mut ErrorResult) -> DOMString {
-        Some(~"Mozilla") // Like Gecko/Webkit
+    pub fn GetAppCodeName(&self) -> Fallible<DOMString> {
+        Ok(Some(~"Mozilla")) // Like Gecko/Webkit
     }
 
-    pub fn GetAppVersion(&self, _rv: &mut ErrorResult) -> DOMString {
-        None
+    pub fn GetAppVersion(&self) -> Fallible<DOMString> {
+        Ok(None)
     }
 
-    pub fn GetPlatform(&self, _rv: &mut ErrorResult) -> DOMString {
-        None
+    pub fn GetPlatform(&self) -> Fallible<DOMString> {
+        Ok(None)
     }
 
-    pub fn GetUserAgent(&self, _rv: &mut ErrorResult) -> DOMString {
-        None
+    pub fn GetUserAgent(&self) -> Fallible<DOMString> {
+        Ok(None)
     }
 
     pub fn GetLanguage(&self) -> DOMString {
diff --git a/src/components/script/dom/node.rs b/src/components/script/dom/node.rs
index 96d2539d99d..d40b85be8e6 100644
--- a/src/components/script/dom/node.rs
+++ b/src/components/script/dom/node.rs
@@ -5,7 +5,7 @@
 //! The core DOM types. Defines the basic DOM hierarchy as well as all the HTML elements.
 
 use dom::bindings::node;
-use dom::bindings::utils::{WrapperCache, DOMString, ErrorResult, NotFound, HierarchyRequest};
+use dom::bindings::utils::{WrapperCache, DOMString, ErrorResult, Fallible, NotFound, HierarchyRequest};
 use dom::bindings::utils::{BindingObject, CacheableWrapper, null_str_as_empty};
 use dom::characterdata::CharacterData;
 use dom::document::AbstractDocument;
@@ -559,7 +559,8 @@ impl Node<ScriptView> {
         None
     }
 
-    pub fn SetNodeValue(&mut self, _val: &DOMString, _rv: &mut ErrorResult) {
+    pub fn SetNodeValue(&mut self, _val: &DOMString) -> ErrorResult {
+        Ok(())
     }
 
     pub fn GetTextContent(&self, abstract_self: AbstractNode<ScriptView>) -> DOMString {
@@ -592,22 +593,20 @@ impl Node<ScriptView> {
                        abstract_self: AbstractNode<ScriptView>,
                        node: Option<AbstractNode<ScriptView>>) {
         //FIXME: We should batch document notifications that occur here
-        let mut rv = Ok(());
         for child in abstract_self.children() {
-            self.RemoveChild(abstract_self, child, &mut rv);
+            self.RemoveChild(abstract_self, child);
         }
         match node {
             None => {},
             Some(node) => {
-                self.AppendChild(abstract_self, node, &mut rv);
+                self.AppendChild(abstract_self, node);
             }
         }
     }
 
     pub fn SetTextContent(&mut self,
                           abstract_self: AbstractNode<ScriptView>,
-                          value: &DOMString,
-                          _rv: &mut ErrorResult) {
+                          value: &DOMString) -> ErrorResult {
         let is_empty = match value {
             &Some(~"") | &None => true,
             _ => false
@@ -640,9 +639,10 @@ impl Node<ScriptView> {
           }
           DoctypeNodeTypeId => {}
         }
+        Ok(())
     }
 
-    pub fn InsertBefore(&mut self, _node: AbstractNode<ScriptView>, _child: Option<AbstractNode<ScriptView>>, _rv: &mut ErrorResult) -> AbstractNode<ScriptView> {
+    pub fn InsertBefore(&mut self, _node: AbstractNode<ScriptView>, _child: Option<AbstractNode<ScriptView>>) -> Fallible<AbstractNode<ScriptView>> {
         fail!("stub")
     }
 
@@ -656,8 +656,7 @@ impl Node<ScriptView> {
 
     pub fn AppendChild(&mut self,
                        abstract_self: AbstractNode<ScriptView>,
-                       node: AbstractNode<ScriptView>,
-                       rv: &mut ErrorResult) -> AbstractNode<ScriptView> {
+                       node: AbstractNode<ScriptView>) -> Fallible<AbstractNode<ScriptView>> {
         fn is_hierarchy_request_err(this_node: AbstractNode<ScriptView>,
                                    new_child: AbstractNode<ScriptView>) -> bool {
             if new_child.is_doctype() {
@@ -680,35 +679,32 @@ impl Node<ScriptView> {
         }
 
         if is_hierarchy_request_err(abstract_self, node) {
-            *rv = Err(HierarchyRequest);
+            return Err(HierarchyRequest);
         }
 
         // TODO: Should we handle WRONG_DOCUMENT_ERR here?
 
-        if rv.is_ok() {
-            self.wait_until_safe_to_modify_dom();
+        self.wait_until_safe_to_modify_dom();
 
-            // If the node already exists it is removed from current parent node.
-            node.parent_node().map(|parent| parent.remove_child(node));
-            abstract_self.add_child(node);
-            match self.owner_doc {
-                Some(doc) => do node.with_mut_base |node| {
-                    node.add_to_doc(doc);
-                },
-                None => ()
-            }
+        // If the node already exists it is removed from current parent node.
+        node.parent_node().map(|parent| parent.remove_child(node));
+        abstract_self.add_child(node);
+        match self.owner_doc {
+            Some(doc) => do node.with_mut_base |node| {
+                node.add_to_doc(doc);
+            },
+            None => ()
         }
-        node
+        Ok(node)
     }
 
-    pub fn ReplaceChild(&mut self, _node: AbstractNode<ScriptView>, _child: AbstractNode<ScriptView>, _rv: &mut ErrorResult) -> AbstractNode<ScriptView> {
+    pub fn ReplaceChild(&mut self, _node: AbstractNode<ScriptView>, _child: AbstractNode<ScriptView>) -> Fallible<AbstractNode<ScriptView>> {
         fail!("stub")
     }
 
     pub fn RemoveChild(&mut self,
                        abstract_self: AbstractNode<ScriptView>,
-                       node: AbstractNode<ScriptView>,
-                       rv: &mut ErrorResult) -> AbstractNode<ScriptView> {
+                       node: AbstractNode<ScriptView>) -> Fallible<AbstractNode<ScriptView>> {
         fn is_not_found_err(this_node: AbstractNode<ScriptView>,
                             old_child: AbstractNode<ScriptView>) -> bool {
             match old_child.parent_node() {
@@ -718,21 +714,20 @@ impl Node<ScriptView> {
         }
 
         if is_not_found_err(abstract_self, node) {
-            *rv = Err(NotFound);
+            return Err(NotFound);
         }
-        if rv.is_ok() {
-            self.wait_until_safe_to_modify_dom();
 
-            abstract_self.remove_child(node);
-            self.remove_from_doc();
-        }
-        node
+        self.wait_until_safe_to_modify_dom();
+
+        abstract_self.remove_child(node);
+        self.remove_from_doc();
+        Ok(node)
     }
 
     pub fn Normalize(&mut self) {
     }
 
-    pub fn CloneNode(&self, _deep: bool, _rv: &mut ErrorResult) -> AbstractNode<ScriptView> {
+    pub fn CloneNode(&self, _deep: bool) -> Fallible<AbstractNode<ScriptView>> {
         fail!("stub")
     }
 
diff --git a/src/components/script/dom/text.rs b/src/components/script/dom/text.rs
index 5ceedbe7fc0..ae9cf24e02e 100644
--- a/src/components/script/dom/text.rs
+++ b/src/components/script/dom/text.rs
@@ -2,7 +2,7 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-use dom::bindings::utils::{DOMString, ErrorResult, null_str_as_empty};
+use dom::bindings::utils::{DOMString, Fallible, null_str_as_empty};
 use dom::characterdata::CharacterData;
 use dom::node::{AbstractNode, ScriptView, Node, TextNodeTypeId};
 use dom::window::Window;
@@ -20,16 +20,16 @@ impl Text {
         }
     }
 
-    pub fn Constructor(owner: @mut Window, text: &DOMString, _rv: &mut ErrorResult) -> AbstractNode<ScriptView> {
+    pub fn Constructor(owner: @mut Window, text: &DOMString) -> Fallible<AbstractNode<ScriptView>> {
         let cx = owner.page.js_info.get_ref().js_compartment.cx.ptr;
-        unsafe { Node::as_abstract_node(cx, @Text::new(null_str_as_empty(text))) }
+        unsafe { Ok(Node::as_abstract_node(cx, @Text::new(null_str_as_empty(text)))) }
     }
 
-    pub fn SplitText(&self, _offset: u32, _rv: &mut ErrorResult) -> AbstractNode<ScriptView> {
+    pub fn SplitText(&self, _offset: u32) -> Fallible<AbstractNode<ScriptView>> {
         fail!("unimplemented")
     }
 
-    pub fn GetWholeText(&self, _rv: &mut ErrorResult) -> DOMString {
-        None
+    pub fn GetWholeText(&self) -> Fallible<DOMString> {
+        Ok(None)
     }
 }
diff --git a/src/components/script/dom/uievent.rs b/src/components/script/dom/uievent.rs
index c9d67c8d7f9..35cf161fbbc 100644
--- a/src/components/script/dom/uievent.rs
+++ b/src/components/script/dom/uievent.rs
@@ -3,7 +3,7 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 use dom::bindings::codegen::UIEventBinding;
-use dom::bindings::utils::{ErrorResult, DOMString};
+use dom::bindings::utils::{DOMString, Fallible};
 use dom::bindings::utils::{CacheableWrapper, WrapperCache, BindingObject, DerivedWrapper};
 use dom::node::{AbstractNode, ScriptView};
 use dom::event::Event;
@@ -39,10 +39,9 @@ impl UIEvent {
 
     pub fn Constructor(_owner: @mut Window,
                        type_: &DOMString,
-                       init: &UIEventBinding::UIEventInit,
-                       _rv: &mut ErrorResult) -> @mut UIEvent {
-        @mut UIEvent::new(type_, init.parent.bubbles, init.parent.cancelable,
-                          init.view, init.detail)
+                       init: &UIEventBinding::UIEventInit) -> Fallible<@mut UIEvent> {
+        Ok(@mut UIEvent::new(type_, init.parent.bubbles, init.parent.cancelable,
+                             init.view, init.detail))
     }
 
     pub fn GetView(&self) -> Option<@mut WindowProxy> {
@@ -59,8 +58,7 @@ impl UIEvent {
                        cancelable: bool,
                        view: Option<@mut WindowProxy>,
                        detail: i32) {
-        let mut rv = Ok(());
-        self.parent.InitEvent(type_, can_bubble, cancelable, &mut rv);
+        self.parent.InitEvent(type_, can_bubble, cancelable);
         self.can_bubble = can_bubble;
         self.cancelable = cancelable;
         self.view = view;