Use a direct include of strings headers in testing/, third_party/, tools/.

tools/android/forwarder2/device_forwarder_main.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 <signal.h>
 #include <stdio.h>
 #include <stdlib.h>
 
 #include <string>
 
 #include "base/at_exit.h"
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/compiler_specific.h"
 #include "base/logging.h"
-#include "base/stringprintf.h"
 #include "base/strings/string_piece.h"
+#include "base/strings/stringprintf.h"
 #include "base/threading/thread.h"
 #include "tools/android/forwarder2/common.h"
 #include "tools/android/forwarder2/daemon.h"
 #include "tools/android/forwarder2/device_controller.h"
 #include "tools/android/forwarder2/pipe_notifier.h"
 
 namespace forwarder2 {
 namespace {
 
 // Leaky global instance, accessed from the signal handler.
@@ skipping 143 matching lines @@
     return 1;
   return client_delegate.has_failed();
 }
 
 }  // namespace
 }  // namespace forwarder2
 
 int main(int argc, char** argv) {
   return forwarder2::RunDeviceForwarder(argc, argv);
 }