Expose performance.memory in workers

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 21 matching lines @@
 #define WorkerPerformance_h
 
 #include "core/dom/ContextLifecycleObserver.h"
 #include "wtf/PassRefPtr.h"
 #include "wtf/RefCounted.h"
 #include "wtf/RefPtr.h"
 
 namespace WebCore {
 
 class ExecutionContext;
+class MemoryInfo;
 
 class WorkerPerformance : public RefCounted<WorkerPerformance>, public ContextLifecycleObserver {
 public:
     static PassRefPtr<WorkerPerformance> create(ExecutionContext* context) { return adoptRef(new WorkerPerformance(context)); }
     ~WorkerPerformance();
 
     double now() const;
+    PassRefPtr<MemoryInfo> memory() const;
 
 private:
     explicit WorkerPerformance(ExecutionContext*);
 };
 
 }
 
 #endif // WorkerPerformance_h