Remove EditingAppleTabSpan class handling

third_party/WebKit/Source/core/editing/serializers/HTMLInterchange.h

 /*
  * Copyright (C) 2004, 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 16 matching lines @@
 #define HTMLInterchange_h
 
 #include "wtf/Forward.h"
 
 namespace blink {
 
 class Text;
 
 #define AppleInterchangeNewline "Apple-interchange-newline"
 #define AppleConvertedSpace "Apple-converted-space"
-#define AppleTabSpanClass "Apple-tab-span"
 
 enum EAnnotateForInterchange {
   DoNotAnnotateForInterchange,
   AnnotateForInterchange
 };
 
 String convertHTMLTextToInterchangeFormat(const String&, const Text&);
 
 }  // namespace blink
 
 #endif