Tidy up WorkerConsoleAgent's handling of its WorkerGlobalScope reference.

Source/core/inspector/WorkerConsoleAgent.cpp

Index: Source/core/inspector/WorkerConsoleAgent.cpp
diff --git a/Source/core/inspector/WorkerConsoleAgent.cpp b/Source/core/inspector/WorkerConsoleAgent.cpp
index 86fce1b45d57aa9820c709648be0331539579fc9..aa456080f1399fddb9d7967cc49a06a9ff6ee90f 100644
--- a/Source/core/inspector/WorkerConsoleAgent.cpp
+++ b/Source/core/inspector/WorkerConsoleAgent.cpp
@@ -46,6 +46,12 @@ WorkerConsoleAgent::~WorkerConsoleAgent()
 {
 }
 
+void WorkerConsoleAgent::trace(Visitor* visitor)
+{
+    visitor->trace(m_workerGlobalScope);
+    InspectorConsoleAgent::trace(visitor);
+}
+
 ConsoleMessageStorage* WorkerConsoleAgent::messageStorage()
 {
     return m_workerGlobalScope->messageStorage();