Use a direct include of strings headers in chrome_frame/.

chrome_frame/chrome_active_document.cc

 // Copyright (c) 2011 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.
 
 // Implementation of ChromeActiveDocument
 #include "chrome_frame/chrome_active_document.h"
 
 #include <hlink.h>
 #include <htiface.h>
 #include <initguid.h>
 #include <mshtmcid.h>
 #include <shdeprecated.h>
 #include <shlguid.h>
 #include <shlobj.h>
 #include <shobjidl.h>
 #include <tlogstg.h>
 #include <urlmon.h>
 #include <wininet.h>
 
 #include "base/command_line.h"
 #include "base/debug/trace_event.h"
 #include "base/logging.h"
-#include "base/string_util.h"
+#include "base/strings/string_util.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/win/scoped_variant.h"
 #include "chrome/app/chrome_command_ids.h"
 #include "chrome/app/chrome_dll_resource.h"
 #include "chrome/common/automation_messages.h"
 #include "chrome/common/chrome_constants.h"
 #include "chrome/test/automation/browser_proxy.h"
 #include "chrome/test/automation/tab_proxy.h"
 #include "chrome_frame/bho.h"
 #include "chrome_frame/bind_context_info.h"
@@ skipping 1397 matching lines @@
 
   return false;
 }
 
 bool ChromeActiveDocument::IsFirstNavigation(
     const NavigationInfo& new_navigation_info) const {
   return (navigation_info_->url.is_empty() &&
           new_navigation_info.navigation_type ==
               content::NAVIGATION_TYPE_NEW_PAGE);
 }