Remove redundant checking platform

Source/core/rendering/RenderText.cpp

 /*
  * (C) 1999 Lars Knoll (knoll@kde.org)
  * (C) 2000 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007 Apple Inc. All rights reserved.
  * Copyright (C) 2006 Andrew Wellington (proton@wiretapped.net)
  * Copyright (C) 2006 Graham Dennis (graham.dennis@gmail.com)
  *
  * 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
@@ skipping 1635 matching lines @@
         return current - 1;
 
     long result = iterator->preceding(current);
     if (result == TextBreakDone)
         result = current - 1;
 
 
     return result;
 }
 
-#if OS(MACOSX) || OS(POSIX)
+#if OS(POSIX)
 
 #define HANGUL_CHOSEONG_START (0x1100)
 #define HANGUL_CHOSEONG_END (0x115F)
 #define HANGUL_JUNGSEONG_START (0x1160)
 #define HANGUL_JUNGSEONG_END (0x11A2)
 #define HANGUL_JONGSEONG_START (0x11A8)
 #define HANGUL_JONGSEONG_END (0x11F9)
 #define HANGUL_SYLLABLE_START (0xAC00)
 #define HANGUL_SYLLABLE_END (0xD7AF)
 #define HANGUL_JONGSEONG_COUNT (28)
@@ skipping 21 matching lines @@
 inline bool isRegionalIndicator(UChar32 c)
 {
     // National flag emoji each consists of a pair of regional indicator symbols.
     return 0x1F1E6 <= c && c <= 0x1F1FF;
 }
 
 #endif
 
 int RenderText::previousOffsetForBackwardDeletion(int current) const
 {
-#if OS(MACOSX) || OS(POSIX)
+#if OS(POSIX)
     ASSERT(m_text);
     StringImpl& text = *m_text.impl();
     UChar32 character;
     bool sawRegionalIndicator = false;
     while (current > 0) {
         if (U16_IS_TRAIL(text[--current]))
             --current;
         if (current < 0)
             break;
 
@@ skipping 63 matching lines @@
             }
             if (state == HangulStateBreak)
                 break;
 
             --current;
         }
     }
 
     return current;
 #else
-    // Platforms other than Mac or Unix delete by one code point.
+    // Platforms other than Unix-like delete by one code point.
     if (U16_IS_TRAIL(m_text[--current]))
         --current;
     if (current < 0)
         current = 0;
     return current;
 #endif
 }
 
 int RenderText::nextOffset(int current) const
 {
@@ skipping 48 matching lines @@
     }
     secureTextTimer->restartWithNewText(lastTypedCharacterOffset);
 }
 
 PassRefPtr<AbstractInlineTextBox> RenderText::firstAbstractInlineTextBox()
 {
     return AbstractInlineTextBox::getOrCreate(this, m_firstTextBox);
 }
 
 } // namespace WebCore