Scaling and offset fix for FELighting (software and skia paths)

Source/platform/graphics/filters/FELighting.h

Index: Source/platform/graphics/filters/FELighting.h
diff --git a/Source/platform/graphics/filters/FELighting.h b/Source/platform/graphics/filters/FELighting.h
index a50f5a77b40d2d1ea8a73bf6cabbbfe35b472fb8..276bc6126dccacc27c9c78371ab87de690ea74a8 100644
--- a/Source/platform/graphics/filters/FELighting.h
+++ b/Source/platform/graphics/filters/FELighting.h
@@ -61,6 +61,7 @@ protected:
         int widthMultipliedByPixelSize;
         int widthDecreasedByOne;
         int heightDecreasedByOne;
+        const LightSource* lightSource;
 
         inline void topLeft(int offset, IntPoint& normalVector);
         inline void topRow(int offset, IntPoint& normalVector);
@@ -122,6 +123,8 @@ protected:
 private:
     virtual void applySoftware() OVERRIDE;
     virtual bool applySkia() OVERRIDE;
+
+    void getTransform(FloatPoint3D* scale, FloatSize* offset) const;
 };
 
 } // namespace WebCore