Revert 99666 (sync tests started failing on mac10.6:

net/base/dns_reloader.h

Index: net/base/dns_reloader.h
===================================================================
--- net/base/dns_reloader.h	(revision 99676)
+++ net/base/dns_reloader.h	(working copy)
@@ -1,24 +0,0 @@
-// Copyright (c) 2011 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.
-
-#ifndef NET_BASE_DNS_RELOADER_H_
-#define NET_BASE_DNS_RELOADER_H_
-#pragma once
-
-#include "build/build_config.h"
-
-#if defined(OS_POSIX) && !defined(OS_MACOSX) && !defined(OS_OPENBSD)
-namespace net {
-
-// Call on the network thread before calling DnsReloaderMaybeReload() anywhere.
-void EnsureDnsReloaderInit();
-
-// Call on the worker thread before doing a DNS lookup to reload the
-// resolver for that thread by doing res_ninit() if required.
-void DnsReloaderMaybeReload();
-
-}  // namespace net
-#endif  // defined(OS_POSIX) && !defined(OS_MACOSX) && !defined(OS_OPENBSD)
-
-#endif  // NET_BASE_DNS_RELOADER_H_