Oilpan: Remove unused destructor from non-finalized SharedWorkerPerformance.

Source/modules/performance/SharedWorkerPerformance.h

 /*
  * Copyright (c) 2014, Opera Software ASA. 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 23 matching lines @@
 #include "platform/Supplementable.h"
 
 namespace WebCore {
 
 class ExecutionContext;
 class SharedWorker;
 
 class SharedWorkerPerformance FINAL : public NoBaseWillBeGarbageCollected<SharedWorkerPerformance>, public WillBeHeapSupplement<SharedWorker> {
     WILL_BE_USING_GARBAGE_COLLECTED_MIXIN(SharedWorkerPerformance);
 public:
-    virtual ~SharedWorkerPerformance();
     static SharedWorkerPerformance& from(SharedWorker&);
 
     static double workerStart(ExecutionContext*, SharedWorker&);
     double getWorkerStart(ExecutionContext*, SharedWorker&) const;
 
     void trace(Visitor*) { }
 
 private:
     explicit SharedWorkerPerformance();
     static const char* supplementName();
 
     double m_timeOrigin;
 };
 
 } // namespace WebCore
 
 #endif // SharedWorkerPerformance_h