Added ability to extract SkBitmaps to filter tool

https://codereview.appspot.com/6748043/



git-svn-id: http://skia.googlecode.com/svn/trunk@6021 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/core/SkPictureRecord.h b/src/core/SkPictureRecord.h
index c36c24a..77e0114 100644
--- a/src/core/SkPictureRecord.h
+++ b/src/core/SkPictureRecord.h
@@ -174,8 +174,10 @@
     SkBBoxHierarchy* fBoundingHierarchy;
     SkPictureStateTree* fStateTree;
 
-private:
+    // Allocated in the constructor and managed by this class.
     SkBitmapHeap* fBitmapHeap;
+
+private:
     SkChunkFlatController fFlattenableHeap;
 
     SkMatrixDictionary fMatrices;