Simplify flattening to just write enough to call the factory

tests/LayerRasterizerTest.cpp

 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkDeque.h"
 #include "SkLayerRasterizer.h"
 #include "SkPaint.h"
@@ skipping 15 matching lines @@
         gCount++;
     }
 
     ~DummyRasterizer() {
         // Not threadsafe. Only used in one thread.
         gCount--;
     }
 
     static int GetCount() { return gCount; }
 
-    SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(DummyRasterizer)
+    SK_DECLARE_NOT_FLATTENABLE_PROCS(DummyRasterizer)
 
 private:
-    DummyRasterizer(SkReadBuffer&) {}
-
     static int gCount;
 
     typedef SkRasterizer INHERITED;
 };
 
 int DummyRasterizer::gCount;
 
 // Check to make sure that the SkPaint in the layer has its destructor called.
 DEF_TEST(LayerRasterizer_destructor, reporter) {
     {
@@ skipping 84 matching lines @@
         } else {
             REPORTER_ASSERT(reporter, equals(*recFirstCopy, *recOneLarger));
         }
     }
 }
 
 DEF_TEST(LayerRasterizer_detachEmpty, reporter) {
     SkLayerRasterizer::Builder builder;
     REPORTER_ASSERT(reporter, NULL == builder.detachRasterizer());
 }