Oilpan: Move WorkerClients to the managed heap and trace its supplements.

Source/core/workers/WorkerClients.h

Index: Source/core/workers/WorkerClients.h
diff --git a/Source/core/workers/WorkerClients.h b/Source/core/workers/WorkerClients.h
index 8cc4aa2ff556722556cf841d9dcb7282a2c47319..7a09e2da8b1923838dd47ae1e484712332cf4701 100644
--- a/Source/core/workers/WorkerClients.h
+++ b/Source/core/workers/WorkerClients.h
@@ -39,16 +39,21 @@ namespace WebCore {
 // This is created on the main thread, passed to the worker thread and
 // attached to WorkerGlobalScope when it is created.
 // This class can be used to provide "client" implementations to Workers.
-class WorkerClients : public Supplementable<WorkerClients> {
+class WorkerClients : public NoBaseWillBeGarbageCollectedFinalized<WorkerClients>, public Supplementable<WorkerClients> {
     WTF_MAKE_NONCOPYABLE(WorkerClients);
 public:
-    static PassOwnPtr<WorkerClients> create()
+    static PassOwnPtrWillBeRawPtr<WorkerClients> create()
     {
-        return adoptPtr(new WorkerClients());
+        return adoptPtrWillBeNoop(new WorkerClients());
     }
 
     virtual ~WorkerClients() { }
 
+    virtual void trace(Visitor* visitor) OVERRIDE
+    {
+        Supplementable<WorkerClients>::trace(visitor);
+    }
+
 private:
     WorkerClients() { }
 };