Allow layout tree changes in container query recalc

Bug: 1146097
Change-Id: I2fbb9d6f41d916fc85b6538f5a3d4545daac40fd
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2624654Reviewed-by: Anders Hartvoll Ruud <andruud@chromium.org>
Commit-Queue: Rune Lillesveen <futhark@chromium.org>
Cr-Commit-Position: refs/heads/master@{#842695}

third_party/blink/renderer/core/dom/node.cc

@@ -1598,7 +1598,8 @@ void Node::AttachLayoutTree(AttachContext& context) {
 }
 
 void Node::DetachLayoutTree(bool performing_reattach) {
-  DCHECK(GetDocument().Lifecycle().StateAllowsDetach());
+  DCHECK(GetDocument().Lifecycle().StateAllowsDetach() ||
+         GetDocument().GetStyleEngine().InContainerQueryStyleRecalc());
   DCHECK(!performing_reattach ||
          GetDocument().GetStyleEngine().InRebuildLayoutTree());
   DocumentLifecycle::DetachScope will_detach(GetDocument().Lifecycle());

third_party/blink/renderer/core/layout/layout_object.cc

@@ -4523,7 +4523,8 @@ void LayoutObject::ClearPaintFlags() {
 }
 
 bool LayoutObject::IsAllowedToModifyLayoutTreeStructure(Document& document) {
-  return document.Lifecycle().StateAllowsLayoutTreeMutations();
+  return document.Lifecycle().StateAllowsLayoutTreeMutations() ||
+         document.GetStyleEngine().InContainerQueryStyleRecalc();
 }
 
 void LayoutObject::SetSubtreeShouldDoFullPaintInvalidation(