Simplify flattening to just write enough to call the factory

src/core/SkEmptyShader.h

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkEmptyShader_DEFINED
 #define SkEmptyShader_DEFINED
 
@@ skipping 12 matching lines @@
     virtual size_t contextSize() const SK_OVERRIDE {
         // Even though createContext returns NULL we have to return a value of at least
         // sizeof(SkShader::Context) to satisfy SkSmallAllocator.
         return sizeof(SkShader::Context);
     }
 
     SK_TO_STRING_OVERRIDE()
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkEmptyShader)
 
 protected:
+#ifdef SK_SUPPORT_LEGACY_DEEPFLATTENING
     SkEmptyShader(SkReadBuffer& buffer) : INHERITED(buffer) {}
+#endif
 
     virtual SkShader::Context* onCreateContext(const ContextRec&, void*) const SK_OVERRIDE {
         return NULL;
     }
 
 private:
     typedef SkShader INHERITED;
 };
 
 #endif