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

chrome/browser/download/download_path_reservation_tracker_unittest.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 "base/file_util.h"
 #include "base/files/file_path.h"
 #include "base/files/scoped_temp_dir.h"
 #include "base/memory/weak_ptr.h"
 #include "base/message_loop.h"
 #include "base/observer_list.h"
-#include "base/stringprintf.h"
+#include "base/strings/stringprintf.h"
 #include "base/test/test_file_util.h"
 #include "chrome/browser/download/download_path_reservation_tracker.h"
 #include "chrome/browser/download/download_target_determiner.h"
 #include "content/public/test/mock_download_item.h"
 #include "content/public/test/test_browser_thread.h"
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 using content::BrowserThread;
 using content::DownloadItem;
@@ skipping 669 matching lines @@
       create_directory,
       conflict_action,
       &reserved_path,
       &verified);
   // We cannot truncate a path with very long extension.
   EXPECT_FALSE(verified);
   item->SetState(DownloadItem::COMPLETE);
 }
 
 #endif