[Editing] Add SelectionTemplate::showTreeForThis()

third_party/WebKit/Source/core/editing/SelectionTemplate.cpp

Index: third_party/WebKit/Source/core/editing/SelectionTemplate.cpp
diff --git a/third_party/WebKit/Source/core/editing/SelectionTemplate.cpp b/third_party/WebKit/Source/core/editing/SelectionTemplate.cpp
index c901ce77248dea86d74f08c3ab6b270f089a9d89..835ab7913246da560978701223e09123937e5c11 100644
--- a/third_party/WebKit/Source/core/editing/SelectionTemplate.cpp
+++ b/third_party/WebKit/Source/core/editing/SelectionTemplate.cpp
@@ -4,6 +4,7 @@
 
 #include "core/editing/SelectionTemplate.h"
 
+#include "core/editing/VisibleSelection.h"
 #include "wtf/Assertions.h"
 #include <ostream>  // NOLINT
 
@@ -103,6 +104,13 @@ bool SelectionTemplate<Strategy>::assertValid() const {
 }
 #endif
 
+#ifndef NDEBUG
+template <typename Strategy>
+void SelectionTemplate<Strategy>::showTreeForThis() const {
+  VisibleSelectionTemplate<Strategy>::showTreeForStartAndEnd(m_base, m_extent);

[yosin_UTC9, 2016/11/28 07:56:27]

We don't want to make |SelectionTemplate| to dependent to |VisibleSelection|.

There are two options:
 - VisibleSelection::showTreeForThis() to call
SelectionTemplate::showTreeForThis()
 - Barand new SelectionTemplate::showTreeForThis(), e.g. "S" and "E" marks
aren't meaningful for |SelectionTemplate| which doesn't have "start" and "end".

+}
+#endif
+
 template <typename Strategy>
 void SelectionTemplate<Strategy>::printTo(std::ostream* ostream,
                                           const char* type) const {