auto merge of #2520 : saneyuki/servo/mut, r=Ms2ger

Related #2514

- This removes needless `&mut self`s from some DOM type method simply.
- This doesn't include some DOM Types which have basis method called from other types (e.g. `Element`). We still have to need to open their changes.
- This does not include to remove an implicit `deref_mut()`.

1 files changed, 2 insertions, 2 deletions

diff --git a/src/components/script/dom/htmllabelelement.rs b/src/components/script/dom/htmllabelelement.rs
index 2896e65da59..69aa07ff631 100644
--- a/src/components/script/dom/htmllabelelement.rs
+++ b/src/components/script/dom/htmllabelelement.rs
@@ -38,7 +38,7 @@ impl HTMLLabelElement {
 
 pub trait HTMLLabelElementMethods {
     fn HtmlFor(&self) -> DOMString;
-    fn SetHtmlFor(&mut self, _html_for: DOMString);
+    fn SetHtmlFor(&self, _html_for: DOMString);
 }
 
 impl<'a> HTMLLabelElementMethods for JSRef<'a, HTMLLabelElement> {
@@ -46,6 +46,6 @@ impl<'a> HTMLLabelElementMethods for JSRef<'a, HTMLLabelElement> {
         "".to_owned()
     }
 
-    fn SetHtmlFor(&mut self, _html_for: DOMString) {
+    fn SetHtmlFor(&self, _html_for: DOMString) {
     }
 }