Templatize FrameSelection::contains function

Source/core/editing/VisibleSelection.h

 /*
  * Copyright (C) 2004 Apple Computer, 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 36 matching lines @@
     public:
         using PositionType = Position;
 
         static bool equalSelections(const VisibleSelection&, const VisibleSelection&);
         static PositionType selectionBase(const VisibleSelection& selection) { return selection.base(); }
         static PositionType selectionExtent(const VisibleSelection& selection) { return selection.extent(); }
         static PositionType selectionStart(const VisibleSelection& selection) { return selection.start(); }
         static PositionType selectionEnd(const VisibleSelection& selection) { return selection.end(); }
         static VisiblePosition selectionVisibleStart(const VisibleSelection& selection) { return selection.visibleStart(); }
         static VisiblePosition selectionVisibleEnd(const VisibleSelection& selection) { return selection.visibleEnd(); }
+        static PositionType toPositionType(const Position& position) { return position; }
     };
 
     VisibleSelection();
 
     VisibleSelection(const Position&, EAffinity, bool isDirectional = false);
     VisibleSelection(const Position&, const Position&, EAffinity = SEL_DEFAULT_AFFINITY, bool isDirectional = false);
 
     explicit VisibleSelection(const Range*, EAffinity = SEL_DEFAULT_AFFINITY, bool isDirectional = false);
 
     explicit VisibleSelection(const VisiblePosition&, bool isDirectional = false);
@@ skipping 145 matching lines @@
 
 } // namespace blink
 
 #ifndef NDEBUG
 // Outside the WebCore namespace for ease of invocation from gdb.
 void showTree(const blink::VisibleSelection&);
 void showTree(const blink::VisibleSelection*);
 #endif
 
 #endif // VisibleSelection_h