Oilpan: make Supplementable tracing more regular.

Source/core/workers/WorkerGlobalScope.cpp

Index: Source/core/workers/WorkerGlobalScope.cpp
diff --git a/Source/core/workers/WorkerGlobalScope.cpp b/Source/core/workers/WorkerGlobalScope.cpp
index 907caec79e3cb9ab0eafb951a10ec02bb5a00d44..1b0ab0e1dc6c5f9512f79e679e53d5ad7063c30b 100644
--- a/Source/core/workers/WorkerGlobalScope.cpp
+++ b/Source/core/workers/WorkerGlobalScope.cpp
@@ -326,6 +326,7 @@ ConsoleMessageStorage* WorkerGlobalScope::messageStorage()
 
 void WorkerGlobalScope::trace(Visitor* visitor)
 {
+#if ENABLE(OILPAN)
     visitor->trace(m_console);
     visitor->trace(m_location);
     visitor->trace(m_navigator);
@@ -333,7 +334,8 @@ void WorkerGlobalScope::trace(Visitor* visitor)
     visitor->trace(m_eventQueue);
     visitor->trace(m_workerClients);
     visitor->trace(m_messageStorage);
-    WillBeHeapSupplementable<WorkerGlobalScope>::trace(visitor);
+    HeapSupplementable<WorkerGlobalScope>::trace(visitor);
+#endif
     ExecutionContext::trace(visitor);
     EventTargetWithInlineData::trace(visitor);
 }