WIP: Skeleton for paint offset caching

Source/core/paint/ObjectPainter.h

 // Copyright 2014 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 ObjectPainter_h
 #define ObjectPainter_h
 
 #include "core/style/ComputedStyleConstants.h"
 #include "wtf/Vector.h"
 
 namespace blink {
 
 class Color;
 class GraphicsContext;
 class LayoutPoint;
 class LayoutRect;
 struct PaintInfo;
 class LayoutObject;
 class ComputedStyle;
 
 class ObjectPainter {
 public:
     ObjectPainter(LayoutObject& layoutObject) : m_layoutObject(layoutObject) { }
 
-    void paintOutline(const PaintInfo&, const LayoutRect& objectBounds, const LayoutRect& visualOverflowBounds);
+    // TODO(pdr): Update paintOutline to take a visualOverflowRect and a paintOffset and update the visual overflow in this function instead of at callsites.
+    void paintOutline(const PaintInfo&, const LayoutRect& objectBounds, const LayoutRect& visualOverflowBounds, const LayoutPoint& paintOffset);
     void paintFocusRing(const PaintInfo&, const ComputedStyle&, const Vector<LayoutRect>& focusRingRects);
     void addPDFURLRectIfNeeded(const PaintInfo&, const LayoutPoint& paintOffset);
 
     static void drawLineForBoxSide(GraphicsContext*, int x1, int y1, int x2, int y2, BoxSide, Color, EBorderStyle, int adjbw1, int adjbw2, bool antialias = false);
 
     static LayoutRect outlineBounds(const LayoutRect& objectBounds, const ComputedStyle&);
 
 private:
     static void drawDashedOrDottedBoxSide(GraphicsContext*, int x1, int y1, int x2, int y2,
         BoxSide, Color, int thickness, EBorderStyle, bool antialias);
     static void drawDoubleBoxSide(GraphicsContext*, int x1, int y1, int x2, int y2,
         int length, BoxSide, Color, int thickness, int adjacentWidth1, int adjacentWidth2, bool antialias);
     static void drawRidgeOrGrooveBoxSide(GraphicsContext*, int x1, int y1, int x2, int y2,
         BoxSide, Color, EBorderStyle, int adjacentWidth1, int adjacentWidth2, bool antialias);
     static void drawSolidBoxSide(GraphicsContext*, int x1, int y1, int x2, int y2,
         BoxSide, Color, int adjacentWidth1, int adjacentWidth2, bool antialias);
 
     LayoutObject& m_layoutObject;
 };
 
 } // namespace blink
 
 #endif