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

chrome/browser/storage_monitor/test_volume_mount_watcher_win.h

 // 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.
 //
 // This file contains a subclass of VolumeMountWatcherWin to expose some
 // functionality for testing.
 
 #ifndef CHROME_BROWSER_STORAGE_MONITOR_TEST_VOLUME_MOUNT_WATCHER_WIN_H_
 #define CHROME_BROWSER_STORAGE_MONITOR_TEST_VOLUME_MOUNT_WATCHER_WIN_H_
 
 #include <string>
 #include <vector>
 
-#include "base/string16.h"
+#include "base/strings/string16.h"
 #include "base/synchronization/waitable_event.h"
 #include "chrome/browser/storage_monitor/volume_mount_watcher_win.h"
 
 namespace base {
 class FilePath;
 }
 
 namespace chrome {
 namespace test {
 
@@ skipping 39 matching lines @@
   scoped_ptr<base::WaitableEvent> device_check_complete_event_;
   bool attached_devices_fake_;
 
   DISALLOW_COPY_AND_ASSIGN(TestVolumeMountWatcherWin);
 };
 
 }  // namespace test
 }  // namespace chrome
 
 #endif  // CHROME_BROWSER_STORAGE_MONITOR_TEST_VOLUME_MOUNT_WATCHER_WIN_H_