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

google_apis/gaia/gaia_authenticator.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_authenticator.h"
 
 #include <string>
 #include <utility>
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/port.h"
-#include "base/string_split.h"
+#include "base/strings/string_split.h"
 #include "googleurl/src/gurl.h"
 #include "net/base/escape.h"
 #include "net/http/http_status_code.h"
 
 using std::pair;
 using std::string;
 using std::vector;
 
 namespace gaia {
 
@@ skipping 367 matching lines @@
 
 bool GaiaAuthenticator::Authenticate(const string& user_name,
                                      const string& password) {
   DCHECK_EQ(MessageLoop::current(), message_loop_);
   const string empty;
   return Authenticate(user_name, password, empty,
                       empty);
 }
 
 }  // namespace gaia