Use a direct include of strings headers in chrome_frame/.

chrome_frame/chrome_frame_activex.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 "chrome_frame/chrome_frame_activex.h"
 
 #include <wininet.h>
 
 #include <algorithm>
 #include <map>
 
 #include "base/basictypes.h"
 #include "base/command_line.h"
 #include "base/debug/trace_event.h"
 #include "base/logging.h"
 #include "base/memory/singleton.h"
 #include "base/path_service.h"
 #include "base/process_util.h"
-#include "base/string_util.h"
-#include "base/stringprintf.h"
 #include "base/strings/string_split.h"
+#include "base/strings/string_util.h"
+#include "base/strings/stringprintf.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/win/scoped_bstr.h"
 #include "base/win/scoped_variant.h"
 #include "chrome/common/automation_messages.h"
 #include "chrome/common/chrome_constants.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/test/automation/tab_proxy.h"
 #include "chrome_frame/utils.h"
 #include "googleurl/src/gurl.h"
 
@@ skipping 662 matching lines @@
   if (FAILED(hr)) {
     NOTREACHED() << "ChromeFrame BHO SetSite failed. Error:"
                  << base::StringPrintf(" 0x%08X", hr);
     return hr;
   }
 
   web_browser2->PutProperty(base::win::ScopedBstr(bho_class_id_as_string),
                             base::win::ScopedVariant(bho));
   return S_OK;
 }