Smaller vtbls in RenderObject

Source/core/rendering/RenderSlider.h

 /*
  * Copyright (C) 2006, 2007, 2008, 2009 Apple Inc. 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.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 21 matching lines @@
 public:
     static const int defaultTrackLength;
 
     explicit RenderSlider(HTMLInputElement*);
     virtual ~RenderSlider();
 
     bool inDragMode() const;
 
 private:
     virtual const char* renderName() const override { return "RenderSlider"; }
-    virtual bool isSlider() const override { return true; }
+    virtual bool isOfType(RenderObjectType type) const override { return type == RenderObjectSlider || RenderFlexibleBox::isOfType(type); }
 
     virtual int baselinePosition(FontBaseline, bool firstLine, LineDirectionMode, LinePositionMode = PositionOnContainingLine) const override;
     virtual void computeIntrinsicLogicalWidths(LayoutUnit& minLogicalWidth, LayoutUnit& maxLogicalWidth) const override;
     virtual void layout() override;
 
     SliderThumbElement* sliderThumbElement() const;
 };
 
 DEFINE_RENDER_OBJECT_TYPE_CASTS(RenderSlider, isSlider());
 
 } // namespace blink
 
 #endif // RenderSlider_h