Use a direct include of strings headers in chromeos/.

chromeos/network/network_profile.cc

 // Copyright (c) 2013 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 "chromeos/network/network_profile.h"
 
 #include "base/logging.h"
-#include "base/stringprintf.h"
+#include "base/strings/stringprintf.h"
 
 namespace chromeos {
 
 std::string NetworkProfile::ToDebugString() const {
   std::string result;
   if (type() == NetworkProfile::TYPE_SHARED) {
     return base::StringPrintf("NetworkProfile(SHARED, %s)",
                               path.c_str());
   } else if (type() == NetworkProfile::TYPE_USER) {
     return base::StringPrintf("NetworkProfile(USER, %s, %s)",
                               path.c_str(),
                               userhash.c_str());
   }
   NOTREACHED();
   return std::string();
 }
 
 }  // namespace chromeos