Remove wchar/wstring version of StringPrintf.

base/stringprintf.h

 // Copyright (c) 2011 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.
 
 #ifndef BASE_STRINGPRINTF_H_
 #define BASE_STRINGPRINTF_H_
 
 #include <stdarg.h>   // va_list
 
 #include <string>
 
 #include "base/base_export.h"
 #include "base/compiler_specific.h"
 
 namespace base {
 
 // Return a C++ string given printf-like input.
 BASE_EXPORT std::string StringPrintf(const char* format, ...)
     PRINTF_FORMAT(1, 2);
-BASE_EXPORT std::wstring StringPrintf(const wchar_t* format, ...)
-    WPRINTF_FORMAT(1, 2);
 
 // Return a C++ string given vprintf-like input.
 BASE_EXPORT std::string StringPrintV(const char* format, va_list ap)
     PRINTF_FORMAT(1, 0);
 
 // Store result into a supplied string and return it.
 BASE_EXPORT const std::string& SStringPrintf(std::string* dst,
                                              const char* format, ...)
     PRINTF_FORMAT(2, 3);
-BASE_EXPORT const std::wstring& SStringPrintf(std::wstring* dst,
-                                              const wchar_t* format, ...)
-    WPRINTF_FORMAT(2, 3);
 
 // Append result to a supplied string.
 BASE_EXPORT void StringAppendF(std::string* dst, const char* format, ...)
     PRINTF_FORMAT(2, 3);
-// TODO(evanm): this is only used in a few places in the code;
-// replace with string16 version.
-BASE_EXPORT void StringAppendF(std::wstring* dst, const wchar_t* format, ...)
-    WPRINTF_FORMAT(2, 3);
 
 // Lower-level routine that takes a va_list and appends to a specified
 // string.  All other routines are just convenience wrappers around it.
 BASE_EXPORT void StringAppendV(std::string* dst, const char* format, va_list ap)
     PRINTF_FORMAT(2, 0);
-BASE_EXPORT void StringAppendV(std::wstring* dst,
-                               const wchar_t* format, va_list ap)
-    WPRINTF_FORMAT(2, 0);
 
 }  // namespace base
 
 // Don't require the namespace for legacy code. New code should use "base::" or
 // have its own using decl.
 //
 // TODO(brettw) remove these when calling code is converted.
 using base::StringPrintf;
 
 #endif  // BASE_STRINGPRINTF_H_