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

webkit/tools/test_shell/test_shell_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.
 
 #include "webkit/tools/test_shell/test_shell.h"
 
 #include <windows.h>
 #include <commdlg.h>
 #include <objbase.h>
 #include <process.h>
 #include <shlwapi.h>
 
 #include "base/command_line.h"
 #include "base/containers/stack_container.h"
 #include "base/debug/trace_event.h"
 #include "base/file_util.h"
 #include "base/message_loop.h"
 #include "base/path_service.h"
-#include "base/string_piece.h"
 #include "base/string_util.h"
+#include "base/strings/string_piece.h"
 #include "base/utf_string_conversions.h"
 #include "base/win/resource_util.h"
 #include "breakpad/src/client/windows/handler/exception_handler.h"
 #include "grit/webkit_chromium_resources.h"
 #include "grit/webkit_resources.h"
 #include "net/base/net_module.h"
 #include "net/url_request/url_request_file_job.h"
 #include "skia/ext/bitmap_platform_device.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebFrame.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebView.h"
@@ skipping 705 matching lines @@
 
 bool EnsureFontLoaded(HFONT font) {
   return true;
 }
 
 bool DownloadUrl(const std::string& url, HWND caller_window) {
   return false;
 }
 
 }  // namespace webkit_glue