Fix mouse cursor update timer to be page-global instead of per-frame

Source/core/page/Chrome.h

 /*
  * Copyright (C) 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
  * Copyright (C) 2012, Samsung Electronics. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
@@ skipping 54 matching lines @@
     virtual IntRect viewportToScreen(const IntRect&) const override;
     virtual WebScreenInfo screenInfo() const override;
 
     virtual void scheduleAnimation() override;
 
     void scheduleAnimationForFrame(LocalFrame* localRoot);
 
     void contentsSizeChanged(LocalFrame*, const IntSize&) const;
 
     void setCursor(const Cursor&);
+    Cursor getLastSetCursorForTesting() const;
 
     void setWindowRect(const IntRect&) const;
     IntRect windowRect() const;
 
     IntRect pageRect() const;
 
     void focus() const;
 
     bool canTakeFocus(WebFocusType) const;
     void takeFocus(WebFocusType) const;
@@ skipping 46 matching lines @@
 
     void willBeDestroyed();
 
 private:
     Chrome(Page*, ChromeClient*);
     void notifyPopupOpeningObservers() const;
 
     Page* m_page;
     ChromeClient* m_client;
     Vector<PopupOpeningObserver*> m_popupOpeningObservers;
+    Cursor m_lastSetMouseCursorForTesting;
 };
 
 } // namespace blink
 
 #endif // Chrome_h