base: Move SplitStringUsingSubstr functions from string_util.h to string_split.h

base/string_util.h

 // Copyright (c) 2010 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
 // This file defines utility functions for working with strings.
 
 #ifndef BASE_STRING_UTIL_H_
 #define BASE_STRING_UTIL_H_
 #pragma once
 
@@ skipping 516 matching lines @@
 void SplitStringDontTrim(const std::wstring& str,
                          wchar_t s,
                          std::vector<std::wstring>* r);
 void SplitStringDontTrim(const string16& str,
                          char16 s,
                          std::vector<string16>* r);
 void SplitStringDontTrim(const std::string& str,
                          char s,
                          std::vector<std::string>* r);
 
-// The same as SplitString, but use a substring delimiter instead of a char.
-void SplitStringUsingSubstr(const string16& str,
-                            const string16& s,
-                            std::vector<string16>* r);
-void SplitStringUsingSubstr(const std::string& str,
-                            const std::string& s,
-                            std::vector<std::string>* r);
-
 // Splits a string into its fields delimited by any of the characters in
 // |delimiters|.  Each field is added to the |tokens| vector.  Returns the
 // number of tokens found.
 size_t Tokenize(const std::wstring& str,
                 const std::wstring& delimiters,
                 std::vector<std::wstring>* tokens);
 size_t Tokenize(const string16& str,
                 const string16& delimiters,
                 std::vector<string16>* tokens);
 size_t Tokenize(const std::string& str,
@@ skipping 78 matching lines @@
 #elif defined(WCHAR_T_IS_UTF32)
   typedef uint32 Unsigned;
 #endif
 };
 template<>
 struct ToUnsigned<short> {
   typedef unsigned short Unsigned;
 };
 
 #endif  // BASE_STRING_UTIL_H_