1 files changed, 11 insertions, 0 deletions
diff --git a/layout/painting/RetainedDisplayListBuilder.cpp b/layout/painting/RetainedDisplayListBuilder.cpp
index bb3a896b9a..ca8f37a252 100644
--- a/layout/painting/RetainedDisplayListBuilder.cpp
+++ b/layout/painting/RetainedDisplayListBuilder.cpp
@@ -523,6 +523,17 @@ class MergeState {
     // current ASR, which gets reset during RestoreState(), so we always need
     // to run it again.
     aOutItem->UpdateBounds(mBuilder->Builder());
+
+    if (aOutItem->GetType() == DisplayItemType::TYPE_TRANSFORM) {
+      MOZ_ASSERT(!aNewItem ||
+                 aNewItem->GetType() == DisplayItemType::TYPE_TRANSFORM);
+      MOZ_ASSERT(aOldItem->GetType() == DisplayItemType::TYPE_TRANSFORM);
+      static_cast<nsDisplayTransform*>(aOutItem)->SetContainsASRs(
+          static_cast<nsDisplayTransform*>(aOldItem)->GetContainsASRs() ||
+          (aNewItem
+               ? static_cast<nsDisplayTransform*>(aNewItem)->GetContainsASRs()
+               : false));
+    }
   }
 
   bool ShouldUseNewItem(nsDisplayItem* aNewItem) {