Oilpan: handle WorkerObjectProxy::m_executionContext ref better.

third_party/WebKit/Source/core/workers/WorkerObjectProxy.h

 /*
  * Copyright (C) 2009 Google 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 16 matching lines @@
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #ifndef WorkerObjectProxy_h
 #define WorkerObjectProxy_h
 
 #include "core/CoreExport.h"
 #include "core/dom/MessagePort.h"
 #include "core/workers/WorkerReportingProxy.h"
+#include "platform/heap/Handle.h"
 #include "wtf/PassOwnPtr.h"
 #include "wtf/PassRefPtr.h"
 
 namespace blink {
 
 class ConsoleMessage;
 class ExecutionContext;
 class ExecutionContextTask;
 class WorkerMessagingProxy;
 
@@ skipping 24 matching lines @@
     void workerGlobalScopeStarted(WorkerGlobalScope*) override { }
     void workerGlobalScopeClosed() override;
     void workerThreadTerminated() override;
     void willDestroyWorkerGlobalScope() override { }
 
 protected:
     WorkerObjectProxy(ExecutionContext*, WorkerMessagingProxy*);
 
 private:
     // These objects always outlive this proxy.
+    GC_PLUGIN_IGNORE("553613")
     ExecutionContext* m_executionContext;
     WorkerMessagingProxy* m_messagingProxy;
 };
 
 } // namespace blink
 
 #endif // WorkerObjectProxy_h