First version of bitmap use tracking in SkPictureRecord

src/core/SkPicturePlayback.h

Index: src/core/SkPicturePlayback.h
===================================================================
--- src/core/SkPicturePlayback.h	(revision 13686)
+++ src/core/SkPicturePlayback.h	(working copy)
@@ -31,6 +31,7 @@
 class SkWStream;
 class SkBBoxHierarchy;
 class SkPictureStateTree;
+class SkOffsetTable;
 
 struct SkPictInfo {
     enum Flags {
@@ -107,6 +108,8 @@
     virtual void postDraw(int opIndex);
 #endif
 
+    void preLoadBitmaps(const SkTDArray<void*>& results);
+
 private:
     class TextContainer {
     public:
@@ -225,6 +228,7 @@
     SkTRefArray<SkPaint>* fPaints;
 
     SkData* fOpData;    // opcodes and parameters
+    SkAutoTUnref<SkOffsetTable> fBitmapUseOffsets;
 
     SkPicture** fPictureRefs;
     int fPictureCount;