Oilpan: move Worker objects to the oilpan heap.

Source/core/workers/AbstractWorker.h

Index: Source/core/workers/AbstractWorker.h
diff --git a/Source/core/workers/AbstractWorker.h b/Source/core/workers/AbstractWorker.h
index 213d7c980ae15ca020cc73d9ef42ceeac329f0d4..08d90e31f02ebc71815a6e9e8dc5ecf29e69b44b 100644
--- a/Source/core/workers/AbstractWorker.h
+++ b/Source/core/workers/AbstractWorker.h
@@ -36,6 +36,7 @@
 #include "core/events/EventListener.h"
 #include "core/events/EventTarget.h"
 #include "core/events/ThreadLocalEventNames.h"
+#include "heap/Handle.h"
 #include "wtf/PassRefPtr.h"
 #include "wtf/RefCounted.h"
 #include "wtf/RefPtr.h"
@@ -47,8 +48,8 @@ class ExceptionState;
 class KURL;
 class ExecutionContext;
 
-class AbstractWorker : public RefCounted<AbstractWorker>, public EventTargetWithInlineData, public ActiveDOMObject {
-    REFCOUNTED_EVENT_TARGET(AbstractWorker);
+class AbstractWorker : public RefCountedWillBeRefCountedGarbageCollected<AbstractWorker>, public EventTargetWithInlineData, public ActiveDOMObject {
+    DEFINE_EVENT_TARGET_REFCOUNTING(RefCountedWillBeRefCountedGarbageCollected<AbstractWorker>);
 public:
     // EventTarget APIs
     virtual ExecutionContext* executionContext() const OVERRIDE FINAL { return ActiveDOMObject::executionContext(); }
@@ -58,6 +59,8 @@ public:
     AbstractWorker(ExecutionContext*);
     virtual ~AbstractWorker();
 
+    virtual void trace(Visitor*) { }
+
 protected:
     // Helper function that converts a URL to an absolute URL and checks the result for validity.
     KURL resolveURL(const String& url, ExceptionState&);