net: Cleanup class/struct forward declarations

net/dns/mdns_cache.h

 // Copyright (c) 2013 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_MDNS_CACHE_H_
 #define NET_DNS_MDNS_CACHE_H_
 
 #include <map>
 #include <memory>
 #include <string>
 #include <vector>
 
 #include "base/callback.h"
 #include "base/macros.h"
 #include "base/time/time.h"
 #include "net/base/net_export.h"
 
 namespace net {
 
-class ParsedDnsRecord;
 class RecordParsed;
 
 // mDNS Cache
 // This is a cache of mDNS records. It keeps track of expiration times and is
 // guaranteed not to return expired records. It also has facilities for timely
 // record expiration.
 class NET_EXPORT_PRIVATE MDnsCache {
  public:
   // Key type for the record map. It is a 3-tuple of type, name and optional
   // value ordered by type, then name, then optional value. This allows us to
@@ skipping 78 matching lines @@
   RecordMap mdns_cache_;
 
   base::Time next_expiration_;
 
   DISALLOW_COPY_AND_ASSIGN(MDnsCache);
 };
 
 }  // namespace net
 
 #endif  // NET_DNS_MDNS_CACHE_H_