[S.P.] Use LayoutObject references instead of pointers.

Source/core/paint/SVGClipPainter.h

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef SVGClipPainter_h
 #define SVGClipPainter_h
 
 #include "platform/geometry/FloatRect.h"
 #include "platform/graphics/paint/DisplayItem.h"
 
@@ skipping 10 matching lines @@
         ClipperNotApplied,
         ClipperAppliedPath,
         ClipperAppliedMask
     };
 
     SVGClipPainter(LayoutSVGResourceClipper& clip) : m_clip(clip) { }
 
     // FIXME: Filters are also stateful resources that could benefit from having their state managed
     //        on the caller stack instead of the current hashmap. We should look at refactoring these
     //        into a general interface that can be shared.
-    bool applyStatefulResource(LayoutObject*, GraphicsContext*, ClipperState&);
-    void postApplyStatefulResource(LayoutObject*, GraphicsContext*, ClipperState&);
+    bool applyStatefulResource(const LayoutObject&, GraphicsContext*, ClipperState&);
+    void postApplyStatefulResource(const LayoutObject&, GraphicsContext*, ClipperState&);
 
     // clipPath can be clipped too, but don't have a boundingBox or paintInvalidationRect. So we can't call
     // applyResource directly and use the rects from the object, since they are empty for LayoutSVGResources
     // FIXME: We made applyClippingToContext public because we cannot call applyResource on HTML elements (it asserts on LayoutObject::objectBoundingBox)
-    bool applyClippingToContext(LayoutObject*, const FloatRect&, const FloatRect&, GraphicsContext*, ClipperState&);
+    bool applyClippingToContext(const LayoutObject&, const FloatRect&, const FloatRect&, GraphicsContext*, ClipperState&);
 
 private:
     void drawClipMaskContent(GraphicsContext*, DisplayItemClient, const FloatRect&);
 
     LayoutSVGResourceClipper& m_clip;
 };
 
 } // namespace blink
 
 #endif // SVGClipPainter_h