net: Cleanup class/struct forward declarations

net/dns/dns_session.h

 // 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.
 
 #ifndef NET_DNS_DNS_SESSION_H_
 #define NET_DNS_DNS_SESSION_H_
 
 #include <stdint.h>
 
 #include <memory>
 #include <vector>
 
 #include "base/lazy_instance.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/metrics/bucket_ranges.h"
 #include "base/time/time.h"
 #include "net/base/net_export.h"
 #include "net/base/network_change_notifier.h"
 #include "net/base/rand_callback.h"
 #include "net/dns/dns_config_service.h"
 #include "net/dns/dns_socket_pool.h"
 
 namespace base {
 class BucketRanges;
-class SampleVector;
 }
 
 namespace net {
 
-class ClientSocketFactory;
 class DatagramClientSocket;
 class NetLog;
 struct NetLogSource;
 class StreamSocket;
 
 // Session parameters and state shared between DNS transactions.
 // Ref-counted so that DnsClient::Request can keep working in absence of
 // DnsClient. A DnsSession must be recreated when DnsConfig changes.
 class NET_EXPORT_PRIVATE DnsSession
     : NON_EXPORTED_BASE(public base::RefCounted<DnsSession>),
@@ skipping 114 matching lines @@
     RttBuckets();
   };
   static base::LazyInstance<RttBuckets>::Leaky rtt_buckets_;
 
   DISALLOW_COPY_AND_ASSIGN(DnsSession);
 };
 
 }  // namespace net
 
 #endif  // NET_DNS_DNS_SESSION_H_