Use a direct include of strings headers in base/.

base/version.cc

 // Copyright (c) 2012 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.
 
 #include "base/version.h"
 
 #include <algorithm>
 
 #include "base/logging.h"
-#include "base/string_util.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_split.h"
+#include "base/strings/string_util.h"
 
 namespace base {
 
 namespace {
 
 // Parses the |numbers| vector representing the different numbers
 // inside the version string and constructs a vector of valid integers. It stops
 // when it reaches an invalid item (including the wildcard character). |parsed|
 // is the resulting integer vector. Function returns true if all numbers were
 // parsed successfully, false otherwise.
@@ skipping 144 matching lines @@
   size_t count = components_.size();
   for (size_t i = 0; i < count - 1; ++i) {
     version_str.append(IntToString(components_[i]));
     version_str.append(".");
   }
   version_str.append(IntToString(components_[count - 1]));
   return version_str;
 }
 
 }  // namespace base