Make window.screen property non replaceable

Source/core/frame/Screen.h

 /*
  * Copyright (C) 2007 Apple 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:
  *
  * 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 22 matching lines @@
 #include "bindings/v8/ScriptWrappable.h"
 #include "core/events/EventTarget.h"
 #include "core/frame/DOMWindowProperty.h"
 #include "heap/Handle.h"
 #include "platform/Supplementable.h"
 #include "wtf/PassRefPtr.h"
 #include "wtf/RefCounted.h"
 
 namespace WebCore {
 
+    class Dictionary;
     class LocalFrame;
 
     class Screen FINAL : public RefCountedWillBeRefCountedGarbageCollected<Screen>, public ScriptWrappable, public EventTargetWithInlineData, public DOMWindowProperty, public WillBeHeapSupplementable<Screen> {
         WILL_BE_USING_GARBAGE_COLLECTED_MIXIN(Screen);
         DEFINE_EVENT_TARGET_REFCOUNTING(RefCountedWillBeRefCountedGarbageCollected<Screen>);
     public:
         static PassRefPtrWillBeRawPtr<Screen> create(LocalFrame* frame)
         {
             return adoptRefWillBeRefCountedGarbageCollected(new Screen(frame));
         }
 
         unsigned height() const;
         unsigned width() const;
         unsigned colorDepth() const;
         unsigned pixelDepth() const;
         int availLeft() const;
         int availTop() const;
         unsigned availHeight() const;
         unsigned availWidth() const;
 
         // EventTarget.
         virtual const AtomicString& interfaceName() const OVERRIDE;
         virtual ExecutionContext* executionContext() const OVERRIDE;
 
         void trace(Visitor*);
 
+        // For layout tests.
+        static void setOverrideScreenData(const Dictionary&);
+        static void clearOverrideScreenData();
+
     private:
         explicit Screen(LocalFrame*);
     };
 
 } // namespace WebCore
 
 #endif // Screen_h