Factor painting code out of RenderBox into a new class called BoxPainter.

Source/core/rendering/RenderBox.h

Index: Source/core/rendering/RenderBox.h
diff --git a/Source/core/rendering/RenderBox.h b/Source/core/rendering/RenderBox.h
index 21c870a64f501c9efb5ff8693e4519b93fc55045..1895b1742a27410430b3086d5d7f435275d1a301 100644
--- a/Source/core/rendering/RenderBox.h
+++ b/Source/core/rendering/RenderBox.h
@@ -23,6 +23,7 @@
 #ifndef RenderBox_h
 #define RenderBox_h
 
+#include "core/paint/BoxPainter.h"
 #include "core/rendering/RenderBoxModelObject.h"
 #include "core/rendering/RenderOverflow.h"
 #include "core/rendering/shapes/ShapeOutsideInfo.h"
@@ -30,6 +31,7 @@
 
 namespace blink {
 
+class BoxPainter;
 struct PaintInfo;
 class RenderLayerScrollableArea;
 
@@ -623,9 +625,12 @@ public:
             removeFloatingOrPositionedChildFromBlockLists();
     }
 
+    bool backgroundHasOpaqueTopLayer() const;
+
 protected:
     virtual void willBeDestroyed() OVERRIDE;
 
+
     virtual void styleWillChange(StyleDifference, const RenderStyle& newStyle) OVERRIDE;
     virtual void styleDidChange(StyleDifference, const RenderStyle* oldStyle) OVERRIDE;
     virtual void updateFromStyle() OVERRIDE;
@@ -635,28 +640,6 @@ protected:
     virtual bool foregroundIsKnownToBeOpaqueInRect(const LayoutRect& localRect, unsigned maxDepthToTest) const;
     virtual bool computeBackgroundIsKnownToBeObscured() OVERRIDE;
 
-    void paintBackground(const PaintInfo&, const LayoutRect&, const Color& backgroundColor, BackgroundBleedAvoidance = BackgroundBleedNone);
-
-    void paintFillLayer(const PaintInfo&, const Color&, const FillLayer&, const LayoutRect&, BackgroundBleedAvoidance, CompositeOperator, RenderObject* backgroundObject, bool skipBaseColor = false);
-    void paintFillLayers(const PaintInfo&, const Color&, const FillLayer&, const LayoutRect&, BackgroundBleedAvoidance = BackgroundBleedNone, CompositeOperator = CompositeSourceOver, RenderObject* backgroundObject = 0);
-
-    void paintMaskImages(const PaintInfo&, const LayoutRect&);
-    void paintBoxDecorationBackgroundWithRect(PaintInfo&, const LayoutPoint&, const LayoutRect&);
-
-    // Information extracted from RenderStyle for box painting.
-    // These are always needed during box painting and recomputing them takes time.
-    struct BoxDecorationData {
-        BoxDecorationData(const RenderStyle&);
-
-        Color backgroundColor;
-        bool hasBackground;
-        bool hasBorder;
-        bool hasAppearance;
-    };
-
-    BackgroundBleedAvoidance determineBackgroundBleedAvoidance(GraphicsContext*, const BoxDecorationData&) const;
-    bool backgroundHasOpaqueTopLayer() const;
-
     void computePositionedLogicalWidth(LogicalExtentComputedValues&) const;
 
     LayoutUnit computeIntrinsicLogicalWidthUsing(const Length& logicalWidthLength, LayoutUnit availableLogicalWidth, LayoutUnit borderAndPadding) const;
@@ -667,8 +650,6 @@ protected:
     virtual void mapLocalToContainer(const RenderLayerModelObject* paintInvalidationContainer, TransformState&, MapCoordinatesFlags = ApplyContainerFlip, bool* wasFixed = 0, const PaintInvalidationState* = 0) const OVERRIDE;
     virtual void mapAbsoluteToLocalPoint(MapCoordinatesFlags, TransformState&) const OVERRIDE;
 
-    void paintRootBoxFillLayers(const PaintInfo&);
-
     RenderObject* splitAnonymousBoxesAroundChild(RenderObject* beforeChild);
 
     virtual void addLayerHitTestRects(LayerHitTestRects&, const RenderLayer* currentCompositedLayer, const LayoutPoint& layerOffset, const LayoutRect& containerRect) const OVERRIDE;
@@ -764,6 +745,7 @@ protected:
 
 private:
     OwnPtr<RenderBoxRareData> m_rareData;
+    BoxPainter m_boxPainter;
 };
 
 DEFINE_RENDER_OBJECT_TYPE_CASTS(RenderBox, isBox());