Oilpan: Remove raw pointer to InProcessWorkerBase from WorkerMessagingProxy

Source/core/workers/InProcessWorkerBase.h

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef InProcessWorkerBase_h
 #define InProcessWorkerBase_h
 
 #include "core/CoreExport.h"
 #include "core/dom/ActiveDOMObject.h"
 #include "core/dom/MessagePort.h"
@@ skipping 40 matching lines @@
     // created proxy. The proxy is expected to manage its own lifetime, and delete itself in response to terminateWorkerGlobalScope().
     virtual WorkerGlobalScopeProxy* createWorkerGlobalScopeProxy(ExecutionContext*) = 0;
 
 private:
     // Callbacks for m_scriptLoader.
     void onResponse();
     void onFinished();
 
     OwnPtr<WorkerScriptLoader> m_scriptLoader;
     RefPtrWillBeMember<ContentSecurityPolicy> m_contentSecurityPolicy;
-    WorkerGlobalScopeProxy* m_contextProxy; // The proxy outlives the worker to perform thread shutdown.
+    RawPtrWillBeMember<WorkerGlobalScopeProxy> m_contextProxy; // The proxy outlives the worker to perform thread shutdown.
 };
 
 } // namespace blink
 
 #endif // InProcessWorkerBase_h