Simplify flattening to just write enough to call the factory

include/effects/SkLightingImageFilter.h

Index: include/effects/SkLightingImageFilter.h
diff --git a/include/effects/SkLightingImageFilter.h b/include/effects/SkLightingImageFilter.h
index 81e8f43f11e5360c6710e2c301d483ca2922d0f4..3e055a80caa29f107b8a0cf19cffe1eb4982beb2 100644
--- a/include/effects/SkLightingImageFilter.h
+++ b/include/effects/SkLightingImageFilter.h
@@ -74,14 +74,16 @@ protected:
                           SkScalar surfaceScale,
                           SkImageFilter* input,
                           const CropRect* cropRect);
+#ifdef SK_SUPPORT_LEGACY_DEEPFLATTENING
     explicit SkLightingImageFilter(SkReadBuffer& buffer);
+#endif
     virtual void flatten(SkWriteBuffer&) const SK_OVERRIDE;
-    const SkLight* light() const { return fLight; }
+    const SkLight* light() const { return fLight.get(); }
     SkScalar surfaceScale() const { return fSurfaceScale; }
 
 private:
     typedef SkImageFilter INHERITED;
-    SkLight* fLight;
+    SkAutoTUnref<SkLight> fLight;
     SkScalar fSurfaceScale;
 };