Implement SkPicture::bytesUsed() for SkRecord backend

include/utils/SkPictureUtils.h

Index: include/utils/SkPictureUtils.h
diff --git a/include/utils/SkPictureUtils.h b/include/utils/SkPictureUtils.h
index c35e1c74090996c8daf1f71f96b4966ef15f7616..9bdf6f69a143041a0d7d8d1d18751b9600ae9a04 100644
--- a/include/utils/SkPictureUtils.h
+++ b/include/utils/SkPictureUtils.h
@@ -78,6 +78,14 @@ public:
      *  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;
+     *  includes nested SkPictures, but does not include large objects that
+     *  SkRecord holds a reference to (e.g. paths, or pixels backing bitmaps).
+     */
+    static size_t ApproximateBytesUsed(const SkPicture* pict);
 };
 
 #endif