Introduce PositionAlgorithm<Strategy>::editingPositionOf()

Source/core/editing/RenderedPosition.cpp

Index: Source/core/editing/RenderedPosition.cpp
diff --git a/Source/core/editing/RenderedPosition.cpp b/Source/core/editing/RenderedPosition.cpp
index 44af6a110b6864f574fde164cb6f6ea2192b0c43..692951e7b218f94117df2565400b29582c7e07be 100644
--- a/Source/core/editing/RenderedPosition.cpp
+++ b/Source/core/editing/RenderedPosition.cpp
@@ -218,9 +218,9 @@ Position RenderedPosition::positionAtLeftBoundaryOfBiDiRun() const
     ASSERT(atLeftBoundaryOfBidiRun());
 
     if (atLeftmostOffsetInBox())
-        return createLegacyEditingPosition(m_layoutObject->node(), m_offset);
+        return Position::editingPositionOf(m_layoutObject->node(), m_offset);
 
-    return createLegacyEditingPosition(nextLeafChild()->layoutObject().node(), nextLeafChild()->caretLeftmostOffset());
+    return Position::editingPositionOf(nextLeafChild()->layoutObject().node(), nextLeafChild()->caretLeftmostOffset());
 }
 
 Position RenderedPosition::positionAtRightBoundaryOfBiDiRun() const
@@ -228,9 +228,9 @@ Position RenderedPosition::positionAtRightBoundaryOfBiDiRun() const
     ASSERT(atRightBoundaryOfBidiRun());
 
     if (atRightmostOffsetInBox())
-        return createLegacyEditingPosition(m_layoutObject->node(), m_offset);
+        return Position::editingPositionOf(m_layoutObject->node(), m_offset);
 
-    return createLegacyEditingPosition(prevLeafChild()->layoutObject().node(), prevLeafChild()->caretRightmostOffset());
+    return Position::editingPositionOf(prevLeafChild()->layoutObject().node(), prevLeafChild()->caretRightmostOffset());
 }
 
 IntRect RenderedPosition::absoluteRect(LayoutUnit* extraWidthToEndOfLine) const