Add SkBBoxRecord subclass that builds up a BBoxHierarchy and PictureStateTree.
Review URL: https://codereview.appspot.com/6490104

git-svn-id: http://skia.googlecode.com/svn/trunk@5500 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/core/SkPictureRecord.h b/src/core/SkPictureRecord.h
index e4420f3..a6e0b68 100644
--- a/src/core/SkPictureRecord.h
+++ b/src/core/SkPictureRecord.h
@@ -16,6 +16,9 @@
 #include "SkTemplates.h"
 #include "SkWriter32.h"
 
+class SkPictureStateTree;
+class SkBBoxHierarchy;
+
 class SkPictureRecord : public SkCanvas {
 public:
     SkPictureRecord(uint32_t recordFlags);
@@ -162,6 +165,13 @@
     void validate() const {}
 #endif
 
+protected:
+
+    // These are set to NULL in our constructor, but may be changed by
+    // subclasses, in which case they will be SkSafeUnref'd in our destructor.
+    SkBBoxHierarchy* fBoundingHierarchy;
+    SkPictureStateTree* fStateTree;
+
 private:
     SkBitmapHeap* fBitmapHeap;
     SkChunkFlatController fFlattenableHeap;