change pixelref to not inherit from SkFlattenable

src/lazy/SkCachingPixelRef.h

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkCachingPixelRef_DEFINED
 #define SkCachingPixelRef_DEFINED
 
@@ skipping 30 matching lines @@
 
 protected:
     virtual ~SkCachingPixelRef();
     virtual bool onNewLockPixels(LockRec*) SK_OVERRIDE;
     virtual void onUnlockPixels() SK_OVERRIDE;
     virtual bool onLockPixelsAreWritable() const SK_OVERRIDE { return false; }
 
     virtual SkData* onRefEncodedData() SK_OVERRIDE {
         return fImageGenerator->refEncodedData();
     }
+
+#ifdef SK_SUPPORT_LEGACY_PIXELREF_UNFLATTENABLE
     // No need to flatten this object. When flattening an SkBitmap,
     // SkWriteBuffer will check the encoded data and write that
     // instead.
     // Future implementations of SkWriteBuffer will need to
     // special case for onRefEncodedData as well.
     SK_DECLARE_UNFLATTENABLE_OBJECT()
+#endif
 
 private:
     SkImageGenerator* const fImageGenerator;
     bool                    fErrorInDecoding;
     void*                   fScaledCacheId;
     const size_t            fRowBytes;
 
     SkCachingPixelRef(const SkImageInfo&, SkImageGenerator*, size_t rowBytes);
 
     typedef SkPixelRef INHERITED;
 };
 
 #endif  // SkCachingPixelRef_DEFINED