Decouple performance() from LocalDOMWindow

Source/core/frame/LocalDOMWindow.h

 /*
  * Copyright (C) 2006, 2007, 2009, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies)
  *
  * 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
@@ skipping 94 matching lines @@
     String status() const override;
     void setStatus(const String&) override;
     String defaultStatus() const override;
     void setDefaultStatus(const String&) override;
     Document* document() const override;
     StyleMedia* styleMedia() const override;
     double devicePixelRatio() const override;
     ApplicationCache* applicationCache() const override;
     int orientation() const override;
     Console* console() const override;
-    Performance* performance() const override;
     DOMWindowCSS* css() const override;
     DOMSelection* getSelection() override;
     void focus(ExecutionContext*) override;
     void blur() override;
     void close(ExecutionContext*) override;
     void print() override;
     void stop() override;
     void alert(const String& message = String()) override;
     bool confirm(const String& message) override;
     String prompt(const String& message, const String& defaultValue) override;
@@ skipping 162 matching lines @@
     mutable RefPtrWillBeMember<BarProp> m_toolbar;
     mutable RefPtrWillBeMember<Console> m_console;
     mutable RefPtrWillBeMember<Navigator> m_navigator;
     mutable RefPtrWillBeMember<StyleMedia> m_media;
 
     String m_status;
     String m_defaultStatus;
 
     mutable RefPtrWillBeMember<ApplicationCache> m_applicationCache;
 
-    mutable RefPtrWillBeMember<Performance> m_performance;
-
     mutable RefPtrWillBeMember<DOMWindowCSS> m_css;
 
     RefPtrWillBeMember<DOMWindowEventQueue> m_eventQueue;
     RefPtr<SerializedScriptValue> m_pendingStateObject;
 
     WillBeHeapHashSet<OwnPtrWillBeMember<PostMessageTimer>> m_postMessageTimers;
 };
 
 DEFINE_TYPE_CASTS(LocalDOMWindow, DOMWindow, x, x->isLocalDOMWindow(), x.isLocalDOMWindow());
 
 inline String LocalDOMWindow::status() const
 {
     return m_status;
 }
 
 inline String LocalDOMWindow::defaultStatus() const
 {
     return m_defaultStatus;
 }
 
 } // namespace blink
 
 #endif // LocalDOMWindow_h