Make CounterDirectiveMap a class and implement a Clone() method.

third_party/WebKit/Source/core/style/StyleRareNonInheritedData.cpp

 /*
  * Copyright (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 136 matching lines @@
       flexible_box_(o.flexible_box_),
       multi_col_(o.multi_col_),
       transform_(o.transform_),
       will_change_(o.will_change_),
       filter_(o.filter_),
       backdrop_filter_(o.backdrop_filter_),
       grid_(o.grid_),
       grid_item_(o.grid_item_),
       scroll_snap_(o.scroll_snap_),
       content_(o.content_ ? o.content_->Clone() : nullptr),
-      counter_directives_(o.counter_directives_ ? Clone(*o.counter_directives_)
+      counter_directives_(o.counter_directives_ ? o.counter_directives_->Clone()
                                                 : nullptr),
       animations_(o.animations_ ? o.animations_->Clone() : nullptr),
       transitions_(o.transitions_ ? o.transitions_->Clone() : nullptr),
       box_shadow_(o.box_shadow_),
       box_reflect_(o.box_reflect_),
       shape_outside_(o.shape_outside_),
       clip_path_(o.clip_path_),
       mask_(o.mask_),
       mask_box_image_(o.mask_box_image_),
       page_size_(o.page_size_),
@@ skipping 120 matching lines @@
          requires_accelerated_compositing_for_external_reasons_ ==
              o.requires_accelerated_compositing_for_external_reasons_ &&
          has_inline_transform_ == o.has_inline_transform_ &&
          resize_ == o.resize_ &&
          has_compositor_proxy_ == o.has_compositor_proxy_ &&
          has_author_background_ == o.has_author_background_ &&
          has_author_border_ == o.has_author_border_;
 }
 
 }  // namespace blink