Have SkPicture inherit from SkRefCnt.

include/core/SkPicture.h

 /*
  * Copyright 2007 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkPicture_DEFINED
 #define SkPicture_DEFINED
 
@@ skipping 10 matching lines @@
 class SkPixelSerializer;
 class SkStream;
 class SkWStream;
 struct SkPictInfo;
 
 /** \class SkPicture
 
     An SkPicture records drawing commands made to a canvas to be played back at a later time.
     This base class handles serialization and a few other miscellany.
 */
-// TODO(mtklein): logically this could be : public SkRefCnt, but that exposes
-// some ref-count adoption bugs in Blink.  Keeping this using SkNVRefCnt
-// happens to stifle them for now.  skia:3847
-class SK_API SkPicture : public SkNVRefCnt<SkPicture> {
+class SK_API SkPicture : public SkRefCnt {
 public:
     virtual ~SkPicture();
 
     /**
      *  Function signature defining a function that sets up an SkBitmap from encoded data. On
      *  success, the SkBitmap should have its Config, width, height, rowBytes and pixelref set.
      *  If the installed pixelref has decoded the data into pixels, then the src buffer need not be
      *  copied. If the pixelref defers the actual decode until its lockPixels() is called, then it
      *  must make a copy of the src buffer.
      *  @param src Encoded data.
@@ skipping 139 matching lines @@
     static bool IsValidPictInfo(const SkPictInfo& info);
     static SkPicture* Forwardport(const SkPictInfo&, const SkPictureData*);
 
     SkPictInfo createHeader() const;
     SkPictureData* backport() const;
 
     mutable uint32_t fUniqueID;
 };
 
 #endif