Enable Oilpan for core/timing/.

Source/modules/performance/WorkerPerformance.h

 /*
  * Copyright (C) 2013 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 32 matching lines @@
 
 class WorkerPerformance final : public GarbageCollected<WorkerPerformance>, public ScriptWrappable {
     DEFINE_WRAPPERTYPEINFO();
 public:
     static WorkerPerformance* create()
     {
         return new WorkerPerformance();
     }
 
     double now(ExecutionContext*) const;
-    PassRefPtrWillBeRawPtr<MemoryInfo> memory() const;
+    MemoryInfo* memory();
 
-    DEFINE_INLINE_TRACE() { }
+    DECLARE_TRACE();
 
 private:
     WorkerPerformance();
+
+    Member<MemoryInfo> m_memoryInfo;
 };
 
 } // namespace blink
 
 #endif // WorkerPerformance_h