Oilpan: Remove raw pointer to InProcessWorkerBase from WorkerMessagingProxy

Source/core/workers/WorkerMessagingProxy.h

 /*
  * Copyright (C) 2008 Apple Inc. All Rights Reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 78 matching lines @@
     void terminateInternally();
 
     // WorkerLoaderProxyProvider
     // These methods are called on different threads to schedule loading
     // requests and to send callbacks back to WorkerGlobalScope.
     void postTaskToLoader(PassOwnPtr<ExecutionContextTask>) override;
     bool postTaskToWorkerGlobalScope(PassOwnPtr<ExecutionContextTask>) override;
 
     RefPtrWillBePersistent<ExecutionContext> m_executionContext;
     OwnPtr<WorkerObjectProxy> m_workerObjectProxy;
-    InProcessWorkerBase* m_workerObject;
+    RawPtrWillBeWeakPersistent<InProcessWorkerBase> m_workerObject;
     bool m_mayBeDestroyed;
     RefPtr<WorkerThread> m_workerThread;
 
     unsigned m_unconfirmedMessageCount; // Unconfirmed messages from worker object to worker thread.
     bool m_workerThreadHadPendingActivity; // The latest confirmation from worker thread reported that it was still active.
 
     bool m_askedToTerminate;
 
     Vector<OwnPtr<ExecutionContextTask>> m_queuedEarlyTasks; // Tasks are queued here until there's a thread object created.
     OwnPtr<WorkerInspectorProxy> m_workerInspectorProxy;
 
     OwnPtrWillBePersistent<WorkerClients> m_workerClients;
 
     RefPtr<WorkerLoaderProxy> m_loaderProxy;
 };
 
 } // namespace blink
 
 #endif // WorkerMessagingProxy_h