Oilpan: move Worker objects to the oilpan heap.

Source/core/workers/SharedWorker.h

Index: Source/core/workers/SharedWorker.h
diff --git a/Source/core/workers/SharedWorker.h b/Source/core/workers/SharedWorker.h
index b19fd41b33210b4bfc574ec30e82a5b8f9ba607a..561695ee194fd6249d63fad7e0a096d19378b52c 100644
--- a/Source/core/workers/SharedWorker.h
+++ b/Source/core/workers/SharedWorker.h
@@ -33,6 +33,7 @@
 #define SharedWorker_h
 
 #include "core/workers/AbstractWorker.h"
+#include "heap/Handle.h"
 #include "platform/Supplementable.h"
 
 namespace WebCore {
@@ -41,7 +42,7 @@ class ExceptionState;
 
 class SharedWorker FINAL : public AbstractWorker, public ScriptWrappable, public Supplementable<SharedWorker> {
 public:
-    static PassRefPtr<SharedWorker> create(ExecutionContext*, const String& url, const String& name, ExceptionState&);
+    static PassRefPtrWillBeRawPtr<SharedWorker> create(ExecutionContext*, const String& url, const String& name, ExceptionState&);
     virtual ~SharedWorker();
 
     MessagePort* port() const { return m_port.get(); }
@@ -53,6 +54,8 @@ public:
     // Allows this SharedWorker + JS wrapper to be garbage collected.
     void unsetPreventGC();
 
+    virtual void trace(Visitor*) OVERRIDE;
+
 private:
     explicit SharedWorker(ExecutionContext*);