Disable caching of failed DNS lookups.

net/base/host_resolver_impl.cc

 // Copyright (c) 2010 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/host_resolver_impl.h"
 
 #if defined(OS_WIN)
 #include <Winsock2.h>
 #elif defined(OS_POSIX)
 #include <netdb.h>
@@ skipping 27 matching lines @@
 namespace net {
 
 namespace {
 
 HostCache* CreateDefaultCache() {
   static const size_t kMaxHostCacheEntries = 100;
 
   HostCache* cache = new HostCache(
       kMaxHostCacheEntries,
       base::TimeDelta::FromMinutes(1),
-      base::TimeDelta::FromMinutes(1));
+      base::TimeDelta::FromSeconds(0));  // Disable caching of failed DNS.
 
   return cache;
 }
 
 }  // anonymous namespace
 
 HostResolver* CreateSystemHostResolver(
     NetworkChangeNotifier* network_change_notifier) {
   // Maximum of 50 concurrent threads.
   // TODO(eroman): Adjust this, do some A/B experiments.
@@ skipping 1095 matching lines @@
     if (r == req)
       return error;
 
     r->OnComplete(error, AddressList());
   }
 
   return ERR_IO_PENDING;
 }
 
 }  // namespace net