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

net/http/http_network_layer.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 "net/http/http_network_layer.h"
 
 #include "base/logging.h"
 #include "base/string_number_conversions.h"
-#include "base/string_split.h"
 #include "base/string_util.h"
+#include "base/strings/string_split.h"
 #include "net/http/http_network_session.h"
 #include "net/http/http_network_transaction.h"
 #include "net/http/http_server_properties_impl.h"
 #include "net/http/http_stream_factory_impl_job.h"
 #include "net/spdy/spdy_framer.h"
 #include "net/spdy/spdy_session.h"
 #include "net/spdy/spdy_session_pool.h"
 
 namespace net {
 
@@ skipping 49 matching lines @@
 
   if (session_)
     session_->CloseIdleConnections();
 }
 
 void HttpNetworkLayer::OnResume() {
   suspended_ = false;
 }
 
 }  // namespace net