Use Position instead of VisiblePosition for SurroundingText.

Source/core/dom/Position.h

 /*
  * Copyright (C) 2004, 2006, 2008 Apple 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 300 matching lines @@
         return offset < anchorNode->maxCharacterOffset();
 
     int currentOffset = 0;
     for (Node* node = anchorNode->firstChild(); node && currentOffset < offset; node = node->nextSibling())
         currentOffset++;
 
 
     return offset < currentOffset;
 }
 
+PassRefPtrWillBeRawPtr<Range> makeRange(const Position&, const Position&);

[Yuta Kitamura, 2014/06/06 08:57:30]

I'm not sure what's the difference between this function and
Range::create(Document&, const Position&, const Position&).

[mlamouri (slow - plz ping), 2014/06/06 09:23:16]

Removed.

+
 class PositionWithAffinity {
     DISALLOW_ALLOCATION();
 public:
     PositionWithAffinity()
         : m_affinity(DOWNSTREAM)
     {
     }
 
     PositionWithAffinity(const Position& position, EAffinity affinity = DOWNSTREAM)
         : m_position(position)
@@ skipping 16 matching lines @@
 
 } // namespace WebCore
 
 #ifndef NDEBUG
 // Outside the WebCore namespace for ease of invocation from gdb.
 void showTree(const WebCore::Position&);
 void showTree(const WebCore::Position*);
 #endif
 
 #endif // Position_h