Use a direct include of utf_string_conversions.h in content/.

content/shell/common/webkit_test_helpers.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/shell/common/webkit_test_helpers.h"
 
 #include "base/command_line.h"
 #include "base/file_util.h"
 #include "base/path_service.h"
-#include "base/utf_string_conversions.h"
+#include "base/strings/utf_string_conversions.h"
 #include "content/shell/common/shell_switches.h"
 #include "third_party/WebKit/Tools/DumpRenderTree/chromium/TestRunner/public/WebPreferences.h"
 #include "webkit/common/webpreferences.h"
 
 namespace content {
 
 void ExportLayoutTestSpecificPreferences(
     const WebTestRunner::WebPreferences& from,
     WebPreferences* to) {
   to->allow_universal_access_from_file_urls =
@@ skipping 114 matching lines @@
           FILE_PATH_LITERAL("Source/WebKit/chromium/webkit/support")))) {
     // We're in a WebKit-only checkout.
     return webkit_path.Append(FILE_PATH_LITERAL("Source/WebKit/chromium"));
   } else {
     // We're in a Chromium checkout, and WebKit is in third_party/WebKit.
     return webkit_path.Append(FILE_PATH_LITERAL("../.."));
   }
 }
 
 }  // namespace content