WebScrollbarThemeClientImpl should not be DisplayItemClient

third_party/WebKit/Source/platform/scroll/Scrollbar.h

 /*
  * Copyright (C) 2004, 2006 Apple Computer, 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
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 27 matching lines @@
 
 class GraphicsContext;
 class HostWindow;
 class IntRect;
 class PlatformGestureEvent;
 class PlatformMouseEvent;
 class ScrollAnimatorBase;
 class ScrollableArea;
 class ScrollbarTheme;
 
-class PLATFORM_EXPORT Scrollbar : public Widget, public ScrollbarThemeClient {
+class PLATFORM_EXPORT Scrollbar : public Widget, public ScrollbarThemeClient, public DisplayItemClient {
 public:
     static Scrollbar* create(ScrollableArea* scrollableArea, ScrollbarOrientation orientation, ScrollbarControlSize size, HostWindow* hostWindow)
     {
         return new Scrollbar(scrollableArea, orientation, size, hostWindow);
     }
 
     // Theme object ownership remains with the caller and it must outlive the scrollbar.
     static Scrollbar* createForTesting(ScrollableArea* scrollableArea, ScrollbarOrientation orientation, ScrollbarControlSize size, ScrollbarTheme* theme)
     {
         return new Scrollbar(scrollableArea, orientation, size, nullptr, theme);
@@ skipping 174 matching lines @@
     bool m_thumbNeedsRepaint;
 
     DISPLAY_ITEM_CACHE_STATUS_IMPLEMENTATION
 };
 
 DEFINE_TYPE_CASTS(Scrollbar, Widget, widget, widget->isScrollbar(), widget.isScrollbar());
 
 } // namespace blink
 
 #endif // Scrollbar_h