Remove base::enable_if

base/template_util.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_TEMPLATE_UTIL_H_
 #define BASE_TEMPLATE_UTIL_H_
 
 #include <cstddef>  // For size_t.
 
 #include "build/build_config.h"
@@ skipping 99 matching lines @@
                         sizeof(internal::YesType)> {
 };
 
 template <typename T>
 struct is_class
     : integral_constant<bool,
                         sizeof(internal::IsClassHelper::Test<T>(0)) ==
                             sizeof(internal::YesType)> {
 };
 
-template<bool B, class T = void>
-struct enable_if {};
-
-template<class T>
-struct enable_if<true, T> { typedef T type; };
-
 }  // namespace base
 
 #endif  // BASE_TEMPLATE_UTIL_H_