Remove currently unused code

src/core/SkPictureRecord.h

Index: src/core/SkPictureRecord.h
===================================================================
--- src/core/SkPictureRecord.h	(revision 14172)
+++ src/core/SkPictureRecord.h	(working copy)
@@ -20,7 +20,6 @@
 #include "SkWriter32.h"
 
 class SkBBoxHierarchy;
-class SkOffsetTable;
 class SkPictureStateTree;
 
 // These macros help with packing and unpacking a single byte value and
@@ -157,7 +156,6 @@
     }
 
     // The command at 'offset' in the skp uses the specified bitmap
-    void trackBitmapUse(int bitmapID, size_t offset);
     int addBitmap(const SkBitmap& bitmap);
     void addMatrix(const SkMatrix& matrix);
     const SkFlatData* addPaint(const SkPaint& paint) { return this->addPaintPtr(&paint); }
@@ -298,8 +296,6 @@
     bool     fOptsEnabled;
     int      fInitialSaveCount;
 
-    SkAutoTUnref<SkOffsetTable> fBitmapUseOffsets;
-
     friend class SkPicturePlayback;
     friend class SkPictureTester; // for unit testing