Revert of Make the simple QUIC client able to resolve hosts.

net/tools/quic/synchronous_host_resolver.h

-// Copyright (c) 2015 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.
-//
-// A simple class for resolving hostname synchronously.
-
-#ifndef NET_TOOLS_QUIC_SYNCHRONOUS_HOST_RESOLVER_H_
-#define NET_TOOLS_QUIC_SYNCHRONOUS_HOST_RESOLVER_H_
-
-#include "net/base/address_list.h"
-#include "net/base/net_export.h"
-#include "net/dns/host_resolver.h"
-
-namespace net {
-
-namespace tools {
-
-class NET_EXPORT_PRIVATE SynchronousHostResolver {
- public:
-  static int Resolve(const std::string& host, AddressList* addresses);
-};
-
-}  // namespace tools
-}  // namespace net
-
-#endif  // NET_TOOLS_QUIC_SYNCHRONOUS_HOST_RESOLVER_H_