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

webkit/tools/test_shell/test_shell_mac.mm

 // 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 <ApplicationServices/ApplicationServices.h>
 #import <Cocoa/Cocoa.h>
 #import <objc/objc-runtime.h>
 #include <sys/stat.h>
 
 #include "webkit/tools/test_shell/test_shell.h"
 
 #include "base/base_paths.h"
 #include "base/basictypes.h"
 #include "base/debug/debugger.h"
 #include "base/file_util.h"
 #include "base/files/file_path.h"
 #include "base/logging.h"
 #include "base/mac/bundle_locations.h"
 #include "base/mac/mac_util.h"
 #include "base/mac/scoped_nsautorelease_pool.h"
 #include "base/message_loop.h"
 #include "base/path_service.h"
 #include "base/string16.h"
-#include "base/string_piece.h"
+#include "base/strings/string_piece.h"
 #include "base/utf_string_conversions.h"
 #include "grit/webkit_resources.h"
 #include "net/base/mime_util.h"
 #include "skia/ext/bitmap_platform_device.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebFrame.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebView.h"
 #include "ui/base/resource/data_pack.h"
 #include "ui/gfx/size.h"
 #include "webkit/glue/webkit_glue.h"
@@ skipping 642 matching lines @@
   return false;
 }
 
 void DidLoadPlugin(const std::string& filename) {
 }
 
 void DidUnloadPlugin(const std::string& filename) {
 }
 
 }  // namespace webkit_glue