Introduce Position constructor with const Node&

third_party/WebKit/Source/core/editing/Position.h

 /*
  * Copyright (C) 2004, 2006, 2008 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 52 matching lines @@
   static const TreeScope* CommonAncestorTreeScope(
       const PositionTemplate<Strategy>&,
       const PositionTemplate<Strategy>& b);
   static PositionTemplate<Strategy> EditingPositionOf(Node* anchor_node,
                                                       int offset);
 
   // For creating before/after positions:
   PositionTemplate(Node* anchor_node, PositionAnchorType);
 
   // For creating offset positions:
-  // FIXME: This constructor should eventually go away. See bug 63040.
-  PositionTemplate(Node* anchor_node, int offset);
+  PositionTemplate(const Node& anchor_node, int offset);
+  // TODO(editing-dev): We should not pass |nullptr| as |anchor_node| for
+  // |Position| constructor.
+  // TODO(editing-dev): This constructor should eventually go away. See bug
+  // http://wkb.ug/63040.
+  PositionTemplate(const Node* anchor_node, int offset);
 
   PositionTemplate(const PositionTemplate&);
 
   PositionAnchorType AnchorType() const { return anchor_type_; }
   bool IsAfterAnchor() const {
     return anchor_type_ == PositionAnchorType::kAfterAnchor;
   }
   bool IsAfterChildren() const {
     return anchor_type_ == PositionAnchorType::kAfterChildren;
   }
@@ skipping 117 matching lines @@
   void ShowTreeForThisInFlatTree() const;
 #endif
 
   DECLARE_TRACE();
 
  private:
   bool IsAfterAnchorOrAfterChildren() const {
     return IsAfterAnchor() || IsAfterChildren();
   }
 
+  // TODO(editing-dev): Since we should consider |Position| is constant in
+  // tree, we should use |Member<const Node>|. see http://crbug.com/735327
   Member<Node> anchor_node_;
   // m_offset can be the offset inside m_anchorNode, or if
   // editingIgnoresContent(m_anchorNode) returns true, then other places in
   // editing will treat m_offset == 0 as "before the anchor" and m_offset > 0 as
   // "after the anchor node".  See parentAnchoredEquivalent for more info.
   int offset_;
   PositionAnchorType anchor_type_;
 };
 
 extern template class CORE_EXTERN_TEMPLATE_EXPORT
@@ skipping 55 matching lines @@
 
 }  // namespace blink
 
 #ifndef NDEBUG
 // Outside the WebCore namespace for ease of invocation from gdb.
 void showTree(const blink::Position&);
 void showTree(const blink::Position*);
 #endif
 
 #endif  // Position_h