Oilpan: move core/workers to oilpan's heap.

Source/web/WebSharedWorkerImpl.h

Index: Source/web/WebSharedWorkerImpl.h
diff --git a/Source/web/WebSharedWorkerImpl.h b/Source/web/WebSharedWorkerImpl.h
index a13e5d7b2c0a40b78381fa64d1fefce0b6a4b929..55619cf025fdad77744218249c4821d85f4532d0 100644
--- a/Source/web/WebSharedWorkerImpl.h
+++ b/Source/web/WebSharedWorkerImpl.h
@@ -112,7 +112,7 @@ private:
 
     WebSharedWorkerClient* client() { return m_client->get(); }
 
-    void setWorkerThread(PassRefPtr<WebCore::WorkerThread> thread) { m_workerThread = thread; }
+    void setWorkerThread(PassRefPtrWillBeRawPtr<WebCore::WorkerThread> thread) { m_workerThread = thread; }
     WebCore::WorkerThread* workerThread() { return m_workerThread.get(); }
 
     // Shuts down the worker thread.
@@ -135,7 +135,7 @@ private:
     WebFrame* m_mainFrame;
     bool m_askedToTerminate;
 
-    RefPtr<WebCore::WorkerThread> m_workerThread;
+    RefPtrWillBePersistent<WebCore::WorkerThread> m_workerThread;
 
     // This one's initialized and bound to the main thread.
     RefPtr<WeakReference<WebSharedWorkerClient> > m_client;