Auto merge of #19164 - emilio:more-traversal-cleanup, r=nox

style: More traversal cleanup.

This is cleanup that allows me to fix https://bugzilla.mozilla.org/show_bug.cgi?id=1415013 in a more straight-forward way.

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components/script/dom/document.rs

@@ -573,8 +573,14 @@ impl Document {
         self.encoding.set(encoding);
     }
 
-    pub fn content_and_heritage_changed(&self, node: &Node, damage: NodeDamage) {
-        node.dirty(damage);
+    pub fn content_and_heritage_changed(&self, node: &Node) {
+        if node.is_in_doc() {
+            node.note_dirty_descendants();
+        }
+
+        // FIXME(emilio): This is very inefficient, ideally the flag above would
+        // be enough and incremental layout could figure out from there.
+        node.dirty(NodeDamage::OtherNodeDamage);
     }
 
     /// Reflows and disarms the timer if the reflow timer has expired.

components/script/dom/node.rs

@@ -483,6 +483,19 @@ impl Node {
         self.flags.set(flags);
     }
 
+    // FIXME(emilio): This and the function below should move to Element.
+    pub fn note_dirty_descendants(&self) {
+        debug_assert!(self.is_in_doc());
+
+        for ancestor in self.inclusive_ancestors() {
+            if ancestor.get_flag(NodeFlags::HAS_DIRTY_DESCENDANTS) {
+                return;
+            }
+
+            ancestor.set_flag(NodeFlags::HAS_DIRTY_DESCENDANTS, true);
+        }
+    }
+
     pub fn has_dirty_descendants(&self) -> bool {
         self.get_flag(NodeFlags::HAS_DIRTY_DESCENDANTS)
     }
@@ -2499,7 +2512,7 @@ impl VirtualMethods for Node {
         if let Some(list) = self.child_list.get() {
             list.as_children_list().children_changed(mutation);
         }
-        self.owner_doc().content_and_heritage_changed(self, NodeDamage::OtherNodeDamage);
+        self.owner_doc().content_and_heritage_changed(self);
     }
 
     // This handles the ranges mentioned in steps 2-3 when removing a node.