Factor remaining filter code of out LayerPainter and into FilterPainter.

Source/core/paint/LayerPainter.h

Index: Source/core/paint/LayerPainter.h
diff --git a/Source/core/paint/LayerPainter.h b/Source/core/paint/LayerPainter.h
index 1b3677b6e52c7806eb96a3a270a54f29ba159e62..fae2c89d0581be795d36203ec145b04166aca746 100644
--- a/Source/core/paint/LayerPainter.h
+++ b/Source/core/paint/LayerPainter.h
@@ -31,6 +31,7 @@ public:
 
     enum BorderRadiusClippingRule { IncludeSelfForBorderRadius, DoNotIncludeSelfForBorderRadius };
     static void applyRoundedRectClips(RenderLayer&, const LayerPaintingInfo&, GraphicsContext*, PaintLayerFlags, ClipRecorder&, BorderRadiusClippingRule = IncludeSelfForBorderRadius);
+    static void beginTransparencyLayers(GraphicsContext*, RenderLayer&, const RenderLayer* rootLayer, const LayoutRect& paintDirtyRect, const LayoutSize& subPixelAccumulation, PaintBehavior);
 
 private:
     enum ClipState { HasNotClipped, HasClipped };
@@ -54,7 +55,6 @@ private:
     void paintMaskForFragments(const LayerFragments&, GraphicsContext*, const LayerPaintingInfo&, RenderObject* paintingRootForRenderer, PaintLayerFlags);
     void paintChildClippingMaskForFragments(const LayerFragments&, GraphicsContext*, const LayerPaintingInfo&, RenderObject* paintingRootForRenderer, PaintLayerFlags);
     void paintTransformedLayerIntoFragments(GraphicsContext*, const LayerPaintingInfo&, PaintLayerFlags);
-    void beginTransparencyLayers(GraphicsContext*, const RenderLayer* rootLayer, const LayoutRect& paintDirtyRect, const LayoutSize& subPixelAccumulation, PaintBehavior);
 
     static bool needsToClip(const LayerPaintingInfo& localPaintingInfo, const ClipRect&);