Implement interfaces in PaintInfo and make it a class.

Source/core/rendering/PaintInfo.h

 /*
  * Copyright (C) 2000 Lars Knoll (knoll@kde.org)
  *           (C) 2000 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Dirk Mueller (mueller@kde.org)
  *           (C) 2004 Allan Sandfeld Jensen (kde@carewolf.com)
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
  * Copyright (C) 2009 Google 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
@@ skipping 43 matching lines @@
         RenderObject* newPaintingRoot = 0, RenderRegion* region = 0, ListHashSet<RenderInline*>* newOutlineObjects = 0,
         OverlapTestRequestMap* overlapTestRequests = 0, const RenderLayerModelObject* newPaintContainer = 0)
         : context(newContext)
         , rect(newRect)
         , phase(newPhase)
         , paintBehavior(newPaintBehavior)
         , paintingRoot(newPaintingRoot)
         , renderRegion(region)
         , outlineObjects(newOutlineObjects)
         , overlapTestRequests(overlapTestRequests)
-        , paintContainer(newPaintContainer)
+        , m_paintContainer(newPaintContainer)
     {
     }
 
     void updatePaintingRootForChildren(const RenderObject* renderer)
     {
         if (!paintingRoot)
             return;
 
         // If we're the painting root, kids draw normally, and see root of 0.
         if (paintingRoot == renderer) {
@@ skipping 19 matching lines @@
 
         context->concatCTM(localToAncestorTransform);
 
         if (rect == infiniteRect())
             return;
 
         rect = localToAncestorTransform.inverse().mapRect(rect);
     }
 
     static IntRect infiniteRect() { return IntRect(LayoutRect::infiniteRect()); }
+    const RenderLayerModelObject* paintContainer() const { return m_paintContainer; }
 
     // FIXME: Introduce setters/getters at some point. Requires a lot of changes throughout rendering/.
     GraphicsContext* context;
     IntRect rect;
     PaintPhase phase;
     PaintBehavior paintBehavior;
     RenderObject* paintingRoot; // used to draw just one element and its visual kids
     RenderRegion* renderRegion;
     ListHashSet<RenderInline*>* outlineObjects; // used to list outlines that should be painted by a block with inline children
     OverlapTestRequestMap* overlapTestRequests;
-    const RenderLayerModelObject* paintContainer; // the layer object that originates the current painting
+
+private:
+
+    const RenderLayerModelObject* m_paintContainer; // the layer object that originates the current painting
 };
 
 } // namespace WebCore
 
 #endif // PaintInfo_h