style: Do not use borrowed types in the selectors::Element trait.

Closes #22972
Closes #23463

components/style/dom.rs

@@ -882,6 +882,13 @@ pub trait TElement:
         hints: &mut V,
     ) where
         V: Push<ApplicableDeclarationBlock>;
+
+    /// Returns element's local name.
+    fn local_name(&self) -> &<SelectorImpl as selectors::parser::SelectorImpl>::BorrowedLocalName;
+
+    /// Returns element's namespace.
+    fn namespace(&self)
+        -> &<SelectorImpl as selectors::parser::SelectorImpl>::BorrowedNamespaceUrl;
 }
 
 /// TNode and TElement aren't Send because we want to be careful and explicit

components/style/gecko/wrapper.rs

@@ -1166,6 +1166,19 @@ impl<'le> TElement for GeckoElement<'le> {
         self.namespace_id() == structs::root::kNameSpaceID_XUL as i32
     }
 
+    #[inline]
+    fn local_name(&self) -> &WeakAtom {
+        unsafe { WeakAtom::new(self.as_node().node_info().mInner.mName) }
+    }
+
+    #[inline]
+    fn namespace(&self) -> &WeakNamespace {
+        unsafe {
+            let namespace_manager = structs::nsContentUtils_sNameSpaceManager;
+            WeakNamespace::new((*namespace_manager).mURIArray[self.namespace_id() as usize].mRawPtr)
+        }
+    }
+
     /// Return the list of slotted nodes of this node.
     #[inline]
     fn slotted_nodes(&self) -> &[Self::ConcreteNode] {
@@ -2071,16 +2084,18 @@ impl<'le> ::selectors::Element for GeckoElement<'le> {
     }
 
     #[inline]
-    fn local_name(&self) -> &WeakAtom {
-        unsafe { WeakAtom::new(self.as_node().node_info().mInner.mName) }
+    fn has_local_name(&self, name: &WeakAtom) -> bool {
+        self.local_name() == name
     }
 
     #[inline]
-    fn namespace(&self) -> &WeakNamespace {
-        unsafe {
-            let namespace_manager = structs::nsContentUtils_sNameSpaceManager;
-            WeakNamespace::new((*namespace_manager).mURIArray[self.namespace_id() as usize].mRawPtr)
-        }
+    fn has_namespace(&self, ns: &WeakNamespace) -> bool {
+        self.namespace() == ns
+    }
+
+    #[inline]
+    fn is_same_type(&self, other: &Self) -> bool {
+        self.local_name() == other.local_name() && self.namespace() == other.namespace()
     }
 
     fn match_non_ts_pseudo_class<F>(

components/style/invalidation/element/element_wrapper.rs

@@ -312,13 +312,24 @@ where
     }
 
     #[inline]
-    fn local_name(&self) -> &<Self::Impl as ::selectors::SelectorImpl>::BorrowedLocalName {
-        self.element.local_name()
+    fn has_local_name(
+        &self,
+        local_name: &<Self::Impl as ::selectors::SelectorImpl>::BorrowedLocalName,
+    ) -> bool {
+        self.element.has_local_name(local_name)
     }
 
     #[inline]
-    fn namespace(&self) -> &<Self::Impl as ::selectors::SelectorImpl>::BorrowedNamespaceUrl {
-        self.element.namespace()
+    fn has_namespace(
+        &self,
+        ns: &<Self::Impl as ::selectors::SelectorImpl>::BorrowedNamespaceUrl,
+    ) -> bool {
+        self.element.has_namespace(ns)
+    }
+
+    #[inline]
+    fn is_same_type(&self, other: &Self) -> bool {
+        self.element.is_same_type(&other.element)
     }
 
     fn attr_matches(