base: Remove 'using' declaration of StringPrintV.

base/stringprintf.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.
 
 #ifndef BASE_STRINGPRINTF_H_
 #define BASE_STRINGPRINTF_H_
 
 #include <stdarg.h>   // va_list
 
 #include <string>
@@ skipping 31 matching lines @@
 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;
-using base::StringPrintV;
 using base::SStringPrintf;
 using base::StringAppendV;
 using base::StringAppendF;
 using base::StringAppendV;
 
 #endif  // BASE_STRINGPRINTF_H_