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

cc/base/spiral_iterator.cc

 // 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.
 
 #include "cc/base/spiral_iterator.h"
 
 #include <algorithm>
 
 namespace cc {
 
@@ skipping 23 matching lines @@
   current_step_ = horizontal_step_count_ - 1;
 
   index_x_ = around_index_rect_.right();
   index_y_ = around_index_rect_.bottom();
 
   // The current index is the bottom right of the around rect, which is also
   // ignored. So we have to advance.
   ++(*this);
 }
 
+SpiralIterator::SpiralIterator(const SpiralIterator& other) = default;
+
+SpiralIterator::SpiralIterator(SpiralIterator&& other) = default;
+
+SpiralIterator::~SpiralIterator() = default;
+
+SpiralIterator& SpiralIterator::operator=(const SpiralIterator& other) =
+    default;
+
+SpiralIterator& SpiralIterator::operator=(SpiralIterator&& other) = default;
+
 SpiralIterator::operator bool() const {
   return index_x_ != -1 && index_y_ != -1;
 }
 
 SpiralIterator& SpiralIterator::operator++() {
   int cannot_hit_consider_count = 0;
   while (cannot_hit_consider_count < 4) {
     if (needs_direction_switch())
       switch_direction();
 
@@ skipping 99 matching lines @@
   current_step_ = 0;
   direction_ = static_cast<Direction>((direction_ + 1) % 4);
 
   if (direction_ == RIGHT || direction_ == LEFT) {
     ++vertical_step_count_;
     ++horizontal_step_count_;
   }
 }
 
 }  // namespace cc