Introduce {next,previous}PositionOf() as replacement of {next,previous}() member functions in Positi

Source/core/editing/Position.h

Index: Source/core/editing/Position.h
diff --git a/Source/core/editing/Position.h b/Source/core/editing/Position.h
index b6dec6faec8576217a631246c545af3f08ce37b5..1a7b840b9ef3ad31c3d302adb6b0584c29d796b3 100644
--- a/Source/core/editing/Position.h
+++ b/Source/core/editing/Position.h
@@ -45,7 +45,7 @@ class Text;
 enum class TextAffinity;
 class TreeScope;
 
-enum PositionMoveType {
+enum class PositionMoveType {
     CodePoint, // Move by a single code point.
     Character, // Move to the next Unicode character break.
     BackwardDeletion // Subject to platform conventions.
@@ -149,12 +149,6 @@ public:
     bool isNotNull() const { return m_anchorNode; }
     bool isOrphan() const { return m_anchorNode && !m_anchorNode->inDocument(); }
 
-    // Move up or down the DOM by one position.
-    // Offsets are computed using layout text for nodes that have layoutObjects - but note that even when
-    // using composed characters, the result may be inside a single user-visible character if a ligature is formed.
-    PositionAlgorithm<Strategy> previous(PositionMoveType = CodePoint) const;
-    PositionAlgorithm<Strategy> next(PositionMoveType = CodePoint) const;
-
     int compareTo(const PositionAlgorithm<Strategy>&) const;
 
     // These can be either inside or just before/after the node, depending on
@@ -407,6 +401,18 @@ inline PositionInComposedTree fromPositionInDOMTree<EditingInComposedTreeStrateg
     return toPositionInComposedTree(position);
 }
 
+// TODO(yosin) We should move |previousPositionOf()| and |nextPositionOf()|
+// to "EditingUtilities.h" with |uncheckedPreviousOffset()| and
+// |uncheckedNextOffset()|.
+// Move up or down the DOM by one position.
+// Offsets are computed using layout text for nodes that have layoutObjects -
+// but note that even when using composed characters, the result may be inside
+// a single user-visible character if a ligature is formed.
+CORE_EXPORT Position previousPositionOf(const Position&, PositionMoveType);
+CORE_EXPORT Position nextPositionOf(const Position&, PositionMoveType);
+CORE_EXPORT PositionInComposedTree previousPositionOf(const PositionInComposedTree&, PositionMoveType);
+CORE_EXPORT PositionInComposedTree nextPositionOf(const PositionInComposedTree&, PositionMoveType);
+
 CORE_EXPORT int uncheckedPreviousOffset(const Node*, int current);
 CORE_EXPORT int uncheckedNextOffset(const Node*, int current);