Follow up to serialization validation code

src/core/SkValidatingReadBuffer.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 SkValidatingReadBuffer_DEFINED
 #define SkValidatingReadBuffer_DEFINED
 
@@ skipping 31 matching lines @@
     virtual int32_t readInt() SK_OVERRIDE;
     virtual SkScalar readScalar() SK_OVERRIDE;
     virtual uint32_t readUInt() SK_OVERRIDE;
     virtual int32_t read32() SK_OVERRIDE;
 
     // strings -- the caller is responsible for freeing the string contents
     virtual void readString(SkString* string) SK_OVERRIDE;
     virtual void* readEncodedString(size_t* length, SkPaint::TextEncoding encoding) SK_OVERRIDE;
 
     // common data structures
-    virtual SkFlattenable* readFlattenable() SK_OVERRIDE;
     virtual void readPoint(SkPoint* point) SK_OVERRIDE;
     virtual void readMatrix(SkMatrix* matrix) SK_OVERRIDE;
     virtual void readIRect(SkIRect* rect) SK_OVERRIDE;
     virtual void readRect(SkRect* rect) SK_OVERRIDE;
     virtual void readRegion(SkRegion* region) SK_OVERRIDE;
     virtual void readPath(SkPath* path) SK_OVERRIDE;
 
     // binary data and arrays
     virtual uint32_t readByteArray(void* value) SK_OVERRIDE;
     virtual uint32_t readColorArray(SkColor* colors) SK_OVERRIDE;
@@ skipping 39 matching lines @@
 
     /**
      *  Provide a function to decode an SkBitmap from encoded data. Only used if the writer
      *  encoded the SkBitmap. If the proper decoder cannot be used, a red bitmap with the
      *  appropriate size will be used.
      */
     void setBitmapDecoder(SkPicture::InstallPixelRefProc bitmapDecoder) {
         fBitmapDecoder = bitmapDecoder;
     }
 
+protected:
+    // Use readFlattenableT to enforce a type check on the flattenable read
+    virtual SkFlattenable* readFlattenable() SK_OVERRIDE;
+
 private:
     void setMemory(const void* data, size_t size);
 
     static bool ptr_align_4(const void* ptr) {
         return (((const char*)ptr - (const char*)NULL) & 3) == 0;
     }
 
     SkReader32 fReader;
     void* fMemoryPtr;
 
@@ skipping 10 matching lines @@
 #ifdef DEBUG_NON_DETERMINISTIC_ASSERT
     // Debugging counter to keep track of how many bitmaps we
     // have decoded.
     int fDecodedBitmapIndex;
 #endif // DEBUG_NON_DETERMINISTIC_ASSERT
 
     typedef SkFlattenableReadBuffer INHERITED;
 };
 
 #endif // SkValidatingReadBuffer_DEFINED