Make DisplayItemClient an interface

third_party/WebKit/Source/web/PageOverlay.h

 /*
  * Copyright (C) 2011 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:
  *
  * 1. Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *
@@ skipping 29 matching lines @@
 
 class GraphicsContext;
 class WebPageOverlay;
 class WebViewImpl;
 
 // Manages a layer that is overlaid on a WebView's content.
 // Clients can paint by implementing WebPageOverlay.
 //
 // With Slimming Paint, internal clients can extract a GraphicsContext to add
 // to the PaintController owned by the GraphicsLayer
-class PageOverlay : public GraphicsLayerClient {
+class PageOverlay : public GraphicsLayerClient, public DisplayItemClient {
 public:
     class Delegate : public GarbageCollectedFinalized<Delegate> {
     public:
         DEFINE_INLINE_VIRTUAL_TRACE() { }
 
         // Paints page overlay contents.
         virtual void paintPageOverlay(const PageOverlay&, GraphicsContext&, const WebSize& webViewSize) const = 0;
         virtual ~Delegate() { }
     };
 
     static PassOwnPtr<PageOverlay> create(WebViewImpl*, PageOverlay::Delegate*);
 
     ~PageOverlay();
 
     void update();
 
     GraphicsLayer* graphicsLayer() const { return m_layer.get(); }
-    DisplayItemClient displayItemClient() const { return toDisplayItemClient(this); }
-    String debugName() const { return "PageOverlay"; }
+    String debugName() const final { return "PageOverlay"; }
 
     // GraphicsLayerClient implementation
     IntRect computeInterestRect(const GraphicsLayer*, const IntRect&) const override;
     void paintContents(const GraphicsLayer*, GraphicsContext&, GraphicsLayerPaintingPhase, const IntRect& interestRect) const override;
     String debugName(const GraphicsLayer*) const override;
 
 private:
     PageOverlay(WebViewImpl*, PageOverlay::Delegate*);
 
     WebViewImpl* m_viewImpl;
     Persistent<PageOverlay::Delegate> m_delegate;
     OwnPtr<GraphicsLayer> m_layer;
 };
 
 } // namespace blink
 
 #endif // PageOverlay_h