[net/dns] Refactoring of job dispatch in HostResolverImpl in preparation for DnsTransactionFactory.

net/base/host_resolver.h

Index: net/base/host_resolver.h
diff --git a/net/base/host_resolver.h b/net/base/host_resolver.h
index a5966103d6a24495a18733be4dd5b09fbe501d10..02b61af75d0f45a3afa4950474220bec3edd765a 100644
--- a/net/base/host_resolver.h
+++ b/net/base/host_resolver.h
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// 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.
 
@@ -182,6 +182,12 @@ NET_EXPORT HostResolver* CreateSystemHostResolver(
     size_t max_retry_attempts,
     NetLog* net_log);
 
+// As above, but the created HostResolver does not use a cache.
+NET_EXPORT HostResolver* CreateNonCachingSystemHostResolver(
+    size_t max_concurrent_resolves,
+    size_t max_retry_attempts,
+    NetLog* net_log);
+
 // Creates a HostResolver implementation that sends actual DNS queries to
 // the specified DNS server and parses response and returns results.
 NET_EXPORT HostResolver* CreateAsyncHostResolver(size_t max_concurrent_resolves,