style: Use Default for ExtraStyleData instead of Option.

components/selectors/context.rs

@@ -131,7 +131,7 @@ where
     pub pseudo_element_matching_fn: Option<&'a Fn(&Impl::PseudoElement) -> bool>,
 
     /// Extra implementation-dependent matching data.
-    pub extra_data: Option<Impl::ExtraMatchingData>,
+    pub extra_data: Impl::ExtraMatchingData,
 
     quirks_mode: QuirksMode,
     classes_and_ids_case_sensitivity: CaseSensitivity,
@@ -176,7 +176,7 @@ where
             scope_element: None,
             nesting_level: 0,
             pseudo_element_matching_fn: None,
-            extra_data: None,
+            extra_data: Default::default(),
             _impl: ::std::marker::PhantomData,
         }
     }

components/selectors/parser.rs

@@ -84,7 +84,7 @@ macro_rules! with_all_bounds {
         /// are parameterized on SelectorImpl. See
         /// <https://github.com/rust-lang/rust/issues/26925>
         pub trait SelectorImpl: Clone + Sized + 'static {
-            type ExtraMatchingData: Sized + 'static;
+            type ExtraMatchingData: Sized + Default + 'static;
             type AttrValue: $($InSelector)*;
             type Identifier: $($InSelector)* + PrecomputedHash;
             type ClassName: $($InSelector)* + PrecomputedHash;

components/style/gecko/wrapper.rs

@@ -2111,10 +2111,8 @@ impl<'le> ::selectors::Element for GeckoElement<'le> {
             }
             NonTSPseudoClass::MozWindowInactive => {
                 let state_bit = DocumentState::NS_DOCUMENT_STATE_WINDOW_INACTIVE;
-                if let Some(ref invalidation_data) = context.extra_data {
+                if context.extra_data.document_state.intersects(state_bit) {
-                    if invalidation_data.document_state.intersects(state_bit) {
+                    return true;
-                        return true;
-                    }
                 }
 
                 self.document_state().contains(state_bit)
@@ -2133,12 +2131,10 @@ impl<'le> ::selectors::Element for GeckoElement<'le> {
             }
             NonTSPseudoClass::MozLocaleDir(ref dir) => {
                 let state_bit = DocumentState::NS_DOCUMENT_STATE_RTL_LOCALE;
-                if let Some(ref invalidation_data) = context.extra_data {
+                if context.extra_data.document_state.intersects(state_bit) {
                     // NOTE(emilio): We could still return false for
                     // Direction::Other(..), but we don't bother.
-                    if invalidation_data.document_state.intersects(state_bit) {
+                    return true;
-                        return true;
-                    }
                 }
 
                 let doc_is_rtl = self.document_state().contains(state_bit);

components/style/invalidation/element/document_state.rs

@@ -19,6 +19,15 @@ pub struct InvalidationMatchingData {
     pub document_state: DocumentState,
 }
 
+impl Default for InvalidationMatchingData {
+    #[inline(always)]
+    fn default() -> Self {
+        Self {
+            document_state: DocumentState::empty(),
+        }
+    }
+}
+
 /// An invalidation processor for style changes due to state and attribute
 /// changes.
 pub struct DocumentStateInvalidationProcessor<'a, E: TElement> {
@@ -46,9 +55,9 @@ impl<'a, E: TElement> DocumentStateInvalidationProcessor<'a, E> {
             quirks_mode,
         );
 
-        matching_context.extra_data = Some(InvalidationMatchingData {
+        matching_context.extra_data = InvalidationMatchingData {
             document_state: document_states_changed,
-        });
+        };
 
         Self { rules, document_states_changed, matching_context }
     }