Simplify flattening to just write enough to call the factory

include/effects/SkMagnifierImageFilter.h

Index: include/effects/SkMagnifierImageFilter.h
diff --git a/include/effects/SkMagnifierImageFilter.h b/include/effects/SkMagnifierImageFilter.h
index 3f799d6555f41914dde7f765bb971682f17fb0cf..9ea4b3748430c82ceae31c198545972442f41d3d 100644
--- a/include/effects/SkMagnifierImageFilter.h
+++ b/include/effects/SkMagnifierImageFilter.h
@@ -14,16 +14,15 @@
 
 class SK_API SkMagnifierImageFilter : public SkImageFilter {
 public:
-    static SkMagnifierImageFilter* Create(const SkRect& srcRect, SkScalar inset,
-                                          SkImageFilter* input = NULL) {
-        return SkNEW_ARGS(SkMagnifierImageFilter, (srcRect, inset, input));
-    }
+    static SkImageFilter* Create(const SkRect& src, SkScalar inset, SkImageFilter* input = NULL);
 
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkMagnifierImageFilter)
 
 protected:
     SkMagnifierImageFilter(const SkRect& srcRect, SkScalar inset, SkImageFilter* input);
+#ifdef SK_SUPPORT_LEGACY_DEEPFLATTENING
     explicit SkMagnifierImageFilter(SkReadBuffer& buffer);
+#endif
     virtual void flatten(SkWriteBuffer&) const SK_OVERRIDE;
 
     virtual bool onFilterImage(Proxy*, const SkBitmap& src, const Context&,