Remove most of FloatingObject.

sky/engine/core/rendering/RenderView.h

Index: sky/engine/core/rendering/RenderView.h
diff --git a/sky/engine/core/rendering/RenderView.h b/sky/engine/core/rendering/RenderView.h
index dc1845158c6e525a78687d248b500e319e834bb9..32849b2ca45802b3daf9af8fb871ead83de425b5 100644
--- a/sky/engine/core/rendering/RenderView.h
+++ b/sky/engine/core/rendering/RenderView.h
@@ -123,8 +123,6 @@ public:
     // Renderer that paints the root background has background-images which all have background-attachment: fixed.
     bool rootBackgroundIsEntirelyFixed() const;
 
-    IntervalArena* intervalArena();
-
     virtual bool backgroundIsKnownToBeOpaqueInRect(const LayoutRect& localRect) const override;
 
     double layoutViewportWidth() const;
@@ -165,7 +163,6 @@ private:
 
     LayoutState* m_layoutState;
     OwnPtr<RenderLayerCompositor> m_compositor;
-    RefPtr<IntervalArena> m_intervalArena;
 
     unsigned m_renderCounterCount;