src/: Update the remaining include paths of string_split.h to its new location.

google_apis/gaia/gaia_auth_util.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 "google_apis/gaia/gaia_auth_util.h"
 
 #include <vector>
 
 #include "base/logging.h"
-#include "base/string_split.h"
 #include "base/string_util.h"
+#include "base/strings/string_split.h"
 #include "google_apis/gaia/gaia_urls.h"
 #include "googleurl/src/gurl.h"
 
 namespace gaia {
 
 namespace {
 const char kGmailDomain[] = "gmail.com";
 }
 
 std::string CanonicalizeEmail(const std::string& email_address) {
@@ skipping 44 matching lines @@
 }
 
 bool IsGaiaSignonRealm(const GURL& url) {
   if (!url.SchemeIsSecure())
     return false;
 
   return url == GURL(GaiaUrls::GetInstance()->gaia_origin_url());
 }
 
 }  // namespace gaia