Tried using CrossThreadPersistent for workerDebuggerAgents

Source/modules/webdatabase/InspectorDatabaseAgent.cpp

Index: Source/modules/webdatabase/InspectorDatabaseAgent.cpp
diff --git a/Source/modules/webdatabase/InspectorDatabaseAgent.cpp b/Source/modules/webdatabase/InspectorDatabaseAgent.cpp
index 7fb02271a8381328df5eb4dc0ea5d8af2c2b803a..73c7b9883026c4bf5e9a60d8504476dad3617061 100644
--- a/Source/modules/webdatabase/InspectorDatabaseAgent.cpp
+++ b/Source/modules/webdatabase/InspectorDatabaseAgent.cpp
@@ -313,4 +313,10 @@ Database* InspectorDatabaseAgent::databaseForId(const String& databaseId)
     return it->value->database();
 }
 
+void InspectorDatabaseAgent::trace(Visitor* visitor)
+{
+    visitor->trace(m_resources);
+    InspectorBaseAgent::trace(visitor);
+}
+
 } // namespace WebCore