content: Update the include paths of base/string_piece.h to its new location.

content/browser/download/save_package.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 "content/browser/download/save_package.h"
 
 #include <algorithm>
 
 #include "base/bind.h"
 #include "base/file_util.h"
 #include "base/files/file_path.h"
 #include "base/i18n/file_util_icu.h"
 #include "base/logging.h"
 #include "base/message_loop.h"
 #include "base/stl_util.h"
-#include "base/string_piece.h"
+#include "base/strings/string_piece.h"
 #include "base/strings/string_split.h"
 #include "base/strings/sys_string_conversions.h"
 #include "base/threading/thread.h"
 #include "base/utf_string_conversions.h"
 #include "content/browser/download/download_item_impl.h"
 #include "content/browser/download/download_manager_impl.h"
 #include "content/browser/download/download_stats.h"
 #include "content/browser/download/save_file.h"
 #include "content/browser/download/save_file_manager.h"
 #include "content/browser/download/save_item.h"
@@ skipping 1405 matching lines @@
 
 void SavePackage::FinalizeDownloadEntry() {
   DCHECK(download_);
   DCHECK(download_manager_);
 
   download_manager_->OnSavePackageSuccessfullyFinished(download_);
   StopObservation();
 }
 
 }  // namespace content