[net] Switch TestURLRequestContext to use MockCachingHostResolver.

net/socket_stream/socket_stream.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.
 //
 // TODO(ukai): code is similar with http_network_transaction.cc.  We should
 //   think about ways to share code, if possible.
 
 #include "net/socket_stream/socket_stream.h"
 
 #include <set>
@@ skipping 228 matching lines @@
   net_log_.AddEvent(NetLog::TYPE_CANCELLED, NULL);
   // We don't need to send pending data when client detach the delegate.
   pending_write_bufs_.clear();
   Close();
 }
 
 const ProxyServer& SocketStream::proxy_server() const {
   return proxy_info_.proxy_server();
 }
 
-void SocketStream::SetHostResolver(HostResolver* host_resolver) {
-  DCHECK(host_resolver);
-  host_resolver_ = host_resolver;
-}
-
 void SocketStream::SetClientSocketFactory(
     ClientSocketFactory* factory) {
   DCHECK(factory);
   factory_ = factory;
 }
 
 void SocketStream::CancelWithError(int error) {
   MessageLoop::current()->PostTask(
       FROM_HERE,
       base::Bind(&SocketStream::DoLoop, this, error));
@@ skipping 953 matching lines @@
 
 SSLConfigService* SocketStream::ssl_config_service() const {
   return context_->ssl_config_service();
 }
 
 ProxyService* SocketStream::proxy_service() const {
   return context_->proxy_service();
 }
 
 }  // namespace net