Use a direct include of strings headers in chrome/browser/r*-s*/.

chrome/browser/storage_monitor/portable_device_watcher_win.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.
 //
 // Any tasks that communicates with the portable device may take >100ms to
 // complete. Those tasks should be run on an blocking thread instead of the
 // UI thread.
 
 #include "chrome/browser/storage_monitor/portable_device_watcher_win.h"
 
 #include <dbt.h>
 #include <portabledevice.h>
 
 #include "base/files/file_path.h"
 #include "base/logging.h"
 #include "base/stl_util.h"
-#include "base/string_util.h"
+#include "base/strings/string_util.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/threading/sequenced_worker_pool.h"
 #include "base/win/scoped_co_mem.h"
 #include "base/win/scoped_comptr.h"
 #include "base/win/scoped_propvariant.h"
 #include "chrome/browser/storage_monitor/media_storage_util.h"
 #include "chrome/browser/storage_monitor/removable_device_constants.h"
 #include "chrome/browser/storage_monitor/storage_info.h"
 #include "content/public/browser/browser_thread.h"
 
@@ skipping 622 matching lines @@
     if (storage_notifications_) {
       storage_notifications_->ProcessDetach(
           storage_map_iter->second.device_id());
     }
     storage_map_.erase(storage_map_iter);
   }
   device_map_.erase(device_iter);
 }
 
 }  // namespace chrome