style: Make InvalidationProcessor methods be &mut self.

This would allow querySelector / querySelectorAll to mutate the list of matched
nodes as it sees fit.

components/style/data.rs

@@ -259,14 +259,14 @@ impl ElementData {
             return InvalidationResult::empty();
         }
 
-        let processor = StateAndAttrInvalidationProcessor;
+        let mut processor = StateAndAttrInvalidationProcessor;
         let invalidator = TreeStyleInvalidator::new(
             element,
             Some(self),
             shared_context,
             stack_limit_checker,
             nth_index_cache,
-            &processor,
+            &mut processor,
         );
 
         let result = invalidator.invalidate();

components/style/invalidation/element/collector.rs

@@ -63,7 +63,7 @@ where
     fn invalidates_on_eager_pseudo_element(&self) -> bool { true }
 
     fn collect_invalidations(
-        &self,
+        &mut self,
         element: E,
         mut data: Option<&mut ElementData>,
         nth_index_cache: Option<&mut NthIndexCache>,
@@ -182,7 +182,7 @@ where
     }
 
     fn should_process_descendants(
-        &self,
+        &mut self,
         _element: E,
         data: Option<&mut ElementData>,
     ) -> bool {
@@ -196,7 +196,7 @@ where
     }
 
     fn recursion_limit_exceeded(
-        &self,
+        &mut self,
         _element: E,
         data: Option<&mut ElementData>,
     ) {
@@ -206,7 +206,7 @@ where
     }
 
     fn invalidated_descendants(
-        &self,
+        &mut self,
         element: E,
         data: Option<&mut ElementData>,
         child: E,
@@ -236,7 +236,7 @@ where
     }
 
     fn invalidated_self(
-        &self,
+        &mut self,
         _element: E,
         data: Option<&mut ElementData>,
     ) {

components/style/invalidation/element/invalidator.rs

@@ -34,7 +34,7 @@ where
     ///
     /// Returns whether the element itself was invalidated.
     fn collect_invalidations(
-        &self,
+        &mut self,
         element: E,
         data: Option<&mut ElementData>,
         nth_index_cache: Option<&mut NthIndexCache>,
@@ -46,7 +46,7 @@ where
     /// Returns whether the invalidation process should process the descendants
     /// of the given element.
     fn should_process_descendants(
-        &self,
+        &mut self,
         element: E,
         data: Option<&mut ElementData>,
     ) -> bool;
@@ -54,21 +54,21 @@ where
     /// Executes an arbitrary action when the recursion limit is exceded (if
     /// any).
     fn recursion_limit_exceeded(
-        &self,
+        &mut self,
         element: E,
         data: Option<&mut ElementData>,
     );
 
     /// Executes an action when `Self` is invalidated.
     fn invalidated_self(
-        &self,
+        &mut self,
         element: E,
         data: Option<&mut ElementData>,
     );
 
     /// Executes an action when any descendant of `Self` is invalidated.
     fn invalidated_descendants(
-        &self,
+        &mut self,
         element: E,
         data: Option<&mut ElementData>,
         child: E,
@@ -96,10 +96,7 @@ where
     shared_context: &'a SharedStyleContext<'b>,
     stack_limit_checker: Option<&'a StackLimitChecker>,
     nth_index_cache: Option<&'a mut NthIndexCache>,
-
-    // TODO(emilio): Make a mutable reference, we're going to need that for
-    // QS/QSA.
-    processor: &'a P,
+    processor: &'a mut P,
 }
 
 /// A vector of invalidations, optimized for small invalidation sets.
@@ -240,7 +237,7 @@ where
         shared_context: &'a SharedStyleContext<'b>,
         stack_limit_checker: Option<&'a StackLimitChecker>,
         nth_index_cache: Option<&'a mut NthIndexCache>,
-        processor: &'a P,
+        processor: &'a mut P,
     ) -> Self {
         Self {
             element,
@@ -359,6 +356,10 @@ where
         invalidations: &InvalidationVector,
         sibling_invalidations: &mut InvalidationVector,
     ) -> bool {
+        let mut invalidations_for_descendants = InvalidationVector::new();
+
+        let mut invalidated_child = false;
+        let invalidated_descendants = {
             let mut child_data = child.mutate_data();
 
             let mut child_invalidator = TreeStyleInvalidator::new(
@@ -370,9 +371,6 @@ where
                 self.processor,
             );
 
-        let mut invalidations_for_descendants = InvalidationVector::new();
-        let mut invalidated_child = false;
-
             invalidated_child |=
                 child_invalidator.process_sibling_invalidations(
                     &mut invalidations_for_descendants,
@@ -386,9 +384,8 @@ where
                     sibling_invalidations,
                 );
 
-        let invalidated_descendants = child_invalidator.invalidate_descendants(
-            &invalidations_for_descendants
-        );
+            child_invalidator.invalidate_descendants(&invalidations_for_descendants)
+        };
 
         // The child may not be a flattened tree child of the current element,
         // but may be arbitrarily deep.