1 files changed, 33 insertions, 0 deletions
diff --git a/components/shared/script/serializable.rs b/components/shared/script/serializable.rs
index d168736f961..8e9f9f5b3da 100644
--- a/components/shared/script/serializable.rs
+++ b/components/shared/script/serializable.rs
@@ -60,6 +60,39 @@ impl FileBlob {
     }
 }
 
+impl crate::BroadcastClone for BlobImpl {
+    type Id = BlobId;
+
+    fn source(
+        data: &crate::StructuredSerializedData,
+    ) -> &Option<std::collections::HashMap<Self::Id, Self>> {
+        &data.blobs
+    }
+
+    fn destination(
+        data: &mut crate::StructuredSerializedData,
+    ) -> &mut Option<std::collections::HashMap<Self::Id, Self>> {
+        &mut data.blobs
+    }
+
+    fn clone_for_broadcast(&self) -> Option<Self> {
+        let type_string = self.type_string();
+
+        if let BlobData::Memory(bytes) = self.blob_data() {
+            let blob_clone = BlobImpl::new_from_bytes(bytes.clone(), type_string);
+
+            // Note: we insert the blob at the original id,
+            // otherwise this will not match the storage key as serialized by SM in `serialized`.
+            // The clone has it's own new Id however.
+            return Some(blob_clone);
+        } else {
+            // Not panicking only because this is called from the constellation.
+            log::warn!("Serialized blob not in memory format(should never happen).");
+        }
+        None
+    }
+}
+
 /// The data backing a DOM Blob.
 #[derive(Debug, Deserialize, MallocSizeOf, Serialize)]
 pub struct BlobImpl {