Move Position::isRenderedCharacter() for Text node to LayoutText

Source/core/layout/LayoutText.h

 /*
  * (C) 1999 Lars Knoll (knoll@kde.org)
  * (C) 2000 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004-2009, 2013 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
@@ skipping 117 matching lines @@
     int previousOffset(int current) const final;
     int previousOffsetForBackwardDeletion(int current) const final;
     int nextOffset(int current) const final;
 
     bool containsReversedText() const { return m_containsReversedText; }
 
     bool isSecure() const { return style()->textSecurity() != TSNONE; }
     void momentarilyRevealLastTypedCharacter(unsigned lastTypedCharacterOffset);
 
     bool isAllCollapsibleWhitespace() const;
+    bool isRenderedCharacter(int offsetInNode) const;
 
     bool canUseSimpleFontCodePath() const { return m_canUseSimpleFontCodePath; }
 
     void removeAndDestroyTextBoxes();
 
     PassRefPtr<AbstractInlineTextBox> firstAbstractInlineTextBox();
 
     float hyphenWidth(const Font&, TextDirection);
 
 protected:
@@ skipping 96 matching lines @@
 inline LayoutText* Text::layoutObject() const
 {
     return toLayoutText(CharacterData::layoutObject());
 }
 
 void applyTextTransform(const ComputedStyle*, String&, UChar);
 
 } // namespace blink
 
 #endif // LayoutText_h