Use a direct include of strings headers in chrome/browser/d*/.

chrome/browser/download/chrome_download_manager_delegate.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 "chrome/browser/download/chrome_download_manager_delegate.h"
 
 #include <string>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/callback.h"
 #include "base/file_util.h"
 #include "base/prefs/pref_member.h"
 #include "base/prefs/pref_service.h"
 #include "base/rand_util.h"
-#include "base/stringprintf.h"
+#include "base/strings/stringprintf.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/time.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/download/download_completion_blocker.h"
 #include "chrome/browser/download/download_crx_util.h"
 #include "chrome/browser/download/download_file_picker.h"
 #include "chrome/browser/download/download_history.h"
 #include "chrome/browser/download/download_path_reservation_tracker.h"
 #include "chrome/browser/download/download_prefs.h"
 #include "chrome/browser/download/download_service.h"
@@ skipping 501 matching lines @@
                     chrome::NOTIFICATION_CRX_INSTALLER_DONE,
                     source);
 
   scoped_refptr<extensions::CrxInstaller> installer =
       content::Source<extensions::CrxInstaller>(source).ptr();
   content::DownloadOpenDelayedCallback callback =
       crx_installers_[installer.get()];
   crx_installers_.erase(installer.get());
   callback.Run(installer->did_handle_successfully());
 }