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

cc/base/spiral_iterator.h

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CC_BASE_SPIRAL_ITERATOR_H_
 #define CC_BASE_SPIRAL_ITERATOR_H_
 
 #include "base/logging.h"
 #include "cc/base/cc_export.h"
 #include "cc/base/index_rect.h"
@@ skipping 15 matching lines @@
 //  3 │ 19│  6│  7│  8│  9│
 //    ├───┼───┼───┼───┼───┤
 //  4 │ 20│ 21│ 22│ 23│ 24│
 //    └───┴───┴───┴───┴───┘
 class CC_EXPORT SpiralIterator {
  public:
   SpiralIterator();
   SpiralIterator(const IndexRect& around_index_rect,
                  const IndexRect& consider_index_rect,
                  const IndexRect& ignore_index_rect);
+  SpiralIterator(const SpiralIterator& other);
+  SpiralIterator(SpiralIterator&& other);
+  ~SpiralIterator();
 
-  ~SpiralIterator() = default;
+  SpiralIterator& operator=(const SpiralIterator& other);
+  SpiralIterator& operator=(SpiralIterator&& other);
 
   operator bool() const;
   SpiralIterator& operator++();
   int index_x() const { return index_x_; }
   int index_y() const { return index_y_; }
 
  private:
   int current_step_count() const {
     return (direction_ == UP || direction_ == DOWN) ? vertical_step_count_
                                                     : horizontal_step_count_;
@@ skipping 14 matching lines @@
   int delta_x_;
   int delta_y_;
   int current_step_;
   int horizontal_step_count_;
   int vertical_step_count_;
 };
 
 }  // namespace cc
 
 #endif  // CC_BASE_SPIRAL_ITERATOR_H_