Make DisplayItemClient an interface

third_party/WebKit/Source/web/WebFontImpl.h

 /*
  * Copyright (C) 2010 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 21 matching lines @@
 #define WebFontImpl_h
 
 #include "platform/fonts/Font.h"
 #include "platform/graphics/paint/DisplayItemClient.h"
 #include "public/web/WebFont.h"
 
 namespace blink {
 
 class FontDescription;
 
-class WebFontImpl final : public WebFont {
+class WebFontImpl final : public WebFont, public DisplayItemClient {
 public:
     explicit WebFontImpl(const FontDescription&);
 
     WebFontDescription fontDescription() const override;
 
     int ascent() const override;
     int descent() const override;
     int height() const override;
     int lineSpacing() const override;
     float xHeight() const override;
 
     void drawText(WebCanvas*, const WebTextRun&, const WebFloatPoint& leftBaseline, WebColor,
         const WebRect& clip) const override;
 
     int calculateWidth(const WebTextRun&) const override;
     int offsetForPosition(const WebTextRun&, float position) const override;
     WebFloatRect selectionRectForText(const WebTextRun&, const WebFloatPoint& leftBaseline,
         int height, int from = 0, int to = -1) const override;
 
-    DisplayItemClient displayItemClient() const { return toDisplayItemClient(this); }
-    String debugName() const { return "WebFontImpl"; }
+    String debugName() const final { return "WebFontImpl"; }
 
 private:
     Font m_font;
 };
 
 } // namespace blink
 
 #endif