Make use of the list of Atoms in ClassSelector

Make use of the list of Atoms in the class attribute selector
(ClassSelector) in selector_matching.

Fixes #3111

1 files changed, 10 insertions, 0 deletions

diff --git a/components/script/dom/attr.rs b/components/script/dom/attr.rs
index 02945088bbb..4da59b96b55 100644
--- a/components/script/dom/attr.rs
+++ b/components/script/dom/attr.rs
@@ -188,6 +188,7 @@ impl<'a> AttrHelpers for JSRef<'a, Attr> {
 pub trait AttrHelpersForLayout {
     unsafe fn value_ref_forever(&self) -> &'static str;
     unsafe fn value_atom_forever(&self) -> Option<Atom>;
+    unsafe fn value_tokens_forever(&self) -> Option<Items<Atom>>;
     unsafe fn local_name_atom_forever(&self) -> Atom;
 }
 
@@ -207,6 +208,15 @@ impl AttrHelpersForLayout for Attr {
         }
     }
 
+    unsafe fn value_tokens_forever(&self) -> Option<Items<Atom>> {
+        // cast to point to T in RefCell<T> directly
+        let value = mem::transmute::<&RefCell<AttrValue>, &AttrValue>(self.value.deref());
+        match *value {
+            TokenListAttrValue(_, ref tokens) => Some(tokens.iter()),
+            _ => None,
+        }
+    }
+
     unsafe fn local_name_atom_forever(&self) -> Atom {
         self.local_name.clone()
     }