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

net/base/mock_host_resolver.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/base/mock_host_resolver.h"
 
 #include <string>
 #include <vector>
 
 #include "base/bind.h"
 #include "base/memory/ref_counted.h"
 #include "base/message_loop.h"
 #include "base/stl_util.h"
-#include "base/string_split.h"
 #include "base/string_util.h"
+#include "base/strings/string_split.h"
 #include "base/threading/platform_thread.h"
 #include "net/base/host_cache.h"
 #include "net/base/net_errors.h"
 #include "net/base/net_util.h"
 #include "net/base/test_completion_callback.h"
 #if defined(OS_WIN)
 #include "net/base/winsock_init.h"
 #endif
 
 namespace net {
@@ skipping 382 matching lines @@
   CHECK_EQ(old_proc, current_proc_);
 }
 
 void ScopedDefaultHostResolverProc::Init(HostResolverProc* proc) {
   current_proc_ = proc;
   previous_proc_ = HostResolverProc::SetDefault(current_proc_);
   current_proc_->SetLastProc(previous_proc_);
 }
 
 }  // namespace net