AU: Manual proxy support

proxy_resolver.cc

 // Copyright (c) 2010 The Chromium OS 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 "update_engine/proxy_resolver.h"
 
+using std::deque;
 using std::string;
-using std::vector;
 
 namespace chromeos_update_engine {
 
 const char kNoProxy[] = "direct://";
 
 bool DirectProxyResolver::GetProxiesForUrl(const string& url,
-                                           vector<string>* out_proxies) {
+                                           deque<string>* out_proxies) {
   out_proxies->clear();
   out_proxies->push_back(kNoProxy);
   return true;
 }
 
 }  // namespace chromeos_update_engine