Remove unused RenderLayer accessors

Source/core/rendering/RenderLayer.h

 /*
  * Copyright (C) 2003, 2009, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2013 Intel Corporation. All rights reserved.
  *
  * Portions are Copyright (C) 1998 Netscape Communications Corporation.
  *
  * Other contributors:
  *   Robert O'Callahan <roc+@cs.cmu.edu>
  *   David Baron <dbaron@fas.harvard.edu>
  *   Christian Biesinger <cbiesinger@web.de>
@@ skipping 107 matching lines @@
 
     void addChild(RenderLayer* newChild, RenderLayer* beforeChild = 0);
     RenderLayer* removeChild(RenderLayer*);
 
     void removeOnlyThisLayer();
     void insertOnlyThisLayer();
 
     void styleChanged(StyleDifference, const RenderStyle* oldStyle);
 
     bool isSelfPaintingLayer() const { return m_isSelfPaintingLayer; }
-    bool isOverflowOnlyLayer() const { return m_layerType == OverflowClipLayer; }
-    bool isForcedLayer() const { return m_layerType == ForcedLayer; }
 
     void setLayerType(LayerType layerType) { m_layerType = layerType; }
 
     bool cannotBlitToWindow() const;
 
     bool isTransparent() const;
     RenderLayer* transparentPaintingAncestor();
     void beginTransparencyLayers(GraphicsContext*, const RenderLayer* rootLayer, const LayoutRect& paintDirtyRect, const LayoutSize& subPixelAccumulation, PaintBehavior);
 
     bool isReflection() const { return renderer()->isReplica(); }
@@ skipping 625 matching lines @@
 
 } // namespace WebCore
 
 #ifndef NDEBUG
 // Outside the WebCore namespace for ease of invocation from gdb.
 void showLayerTree(const WebCore::RenderLayer*);
 void showLayerTree(const WebCore::RenderObject*);
 #endif
 
 #endif // RenderLayer_h