[Editing] Add SelectionTemplate::showTreeForThis()

third_party/WebKit/Source/core/editing/SelectionTemplate.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 SelectionTemplate_h
 #define SelectionTemplate_h
 
 #include "base/macros.h"
 #include "core/CoreExport.h"
 #include "core/editing/EphemeralRange.h"
@@ skipping 82 matching lines @@
   // assertion failure.
   bool assertValid() const;
   bool assertValidFor(const Document&) const;
 
   DEFINE_INLINE_TRACE() {
     visitor->trace(m_base);
     visitor->trace(m_extent);
   }
 
   void printTo(std::ostream*, const char* type) const;
+#ifndef NDEBUG
+  void showTreeForThis() const;
+#endif
 
  private:
   friend class SelectionEditor;
 
   Document* document() const;
 
   PositionTemplate<Strategy> m_base;
   PositionTemplate<Strategy> m_extent;
   TextAffinity m_affinity = TextAffinity::Downstream;
   TextGranularity m_granularity = CharacterGranularity;
@@ skipping 11 matching lines @@
 
 using SelectionInDOMTree = SelectionTemplate<EditingStrategy>;
 using SelectionInFlatTree = SelectionTemplate<EditingInFlatTreeStrategy>;
 
 CORE_EXPORT std::ostream& operator<<(std::ostream&, const SelectionInDOMTree&);
 CORE_EXPORT std::ostream& operator<<(std::ostream&, const SelectionInFlatTree&);
 
 }  // namespace blink
 
 #endif  // SelectionTemplate_h