cc: Implement tile iteration order based on pyramid sequence. [old]

cc/base/reverse_spiral_iterator.h

Index: cc/base/reverse_spiral_iterator.h
diff --git a/cc/base/reverse_spiral_iterator.h b/cc/base/reverse_spiral_iterator.h
index d6c5d9e1d859fb9503ef6d5ef7752c8e5ba3fbbd..7a6389e59d066a76bb095141f7920ffa0d51627b 100644
--- a/cc/base/reverse_spiral_iterator.h
+++ b/cc/base/reverse_spiral_iterator.h
@@ -33,8 +33,12 @@ class CC_EXPORT ReverseSpiralIterator {
   ReverseSpiralIterator(const IndexRect& around_index_rect,
                         const IndexRect& consider_index_rect,
                         const IndexRect& ignore_index_rect);
+  ReverseSpiralIterator(const ReverseSpiralIterator& other);
+  ReverseSpiralIterator(ReverseSpiralIterator&& other);
+  ~ReverseSpiralIterator();
 
-  ~ReverseSpiralIterator() = default;
+  ReverseSpiralIterator& operator=(const ReverseSpiralIterator& other);
+  ReverseSpiralIterator& operator=(ReverseSpiralIterator&& other);
 
   operator bool() const;
   ReverseSpiralIterator& operator++();