Implement SkPicture::bytesUsed() for SkRecord backend

include/utils/SkPictureUtils.h

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkPictureUtils_DEFINED
 #define SkPictureUtils_DEFINED
 
@@ skipping 60 matching lines @@
         SkTDArray<PixelRefAndRect> fArray;
 
         typedef SkPixelRefContainer INHERITED;
     };
 
     /**
      *  Fill the provided pixel ref container with the picture's pixel ref
      *  and rect information.
      */
     static void GatherPixelRefsAndRects(SkPicture* pict, SkPixelRefContainer* prCont);
+
+    /**
+     *  How many bytes are allocated to hold the SkPicture.
+     *  Includes operations, parameters, bounding data, deletion listeners;
+     *  does not include large objects that SkRecord holds a reference to
+     *  (e.g. paths, pixels backing bitmaps).

[mtklein, 2014/11/18 19:26:14]

Might add nested pictures to the list of things we don't count?  Took me a while
to remember that.

[tomhudson, 2014/11/18 19:35:12]

Done.

+     */
+    static size_t ApproximateBytesUsed(const SkPicture* pict);
 };
 
 #endif