Virtual destructors should have virtual keyword.

net/base/dnsrr_resolver.h

 // Copyright (c) 2011 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_BASE_DNSRR_RESOLVER_H_
 #define NET_BASE_DNSRR_RESOLVER_H_
 #pragma once
 
 #include <map>
 #include <string>
@@ skipping 65 matching lines @@
     kInvalidHandle = 0,
   };
 
   enum {
     // Try harder to get a DNSSEC signed response. This doesn't mean that the
     // RRResponse will always have the dnssec bit set.
     FLAG_WANT_DNSSEC = 1,
   };
 
   DnsRRResolver();
-  ~DnsRRResolver();
+  virtual ~DnsRRResolver();
 
   uint64 requests() const { return requests_; }
   uint64 cache_hits() const { return cache_hits_; }
   uint64 inflight_joins() const { return inflight_joins_; }
 
   // Resolve starts the resolution process. When complete, |callback| is called
   // with a result. If the result is |OK| then |response| is filled with the
   // result of the resolution. Note that |callback| is called via the current
   // MessageLoop.
   //
@@ skipping 31 matching lines @@
   uint64 inflight_joins_;
 
   bool in_destructor_;
 
   DISALLOW_COPY_AND_ASSIGN(DnsRRResolver);
 };
 
 }  // namespace net
 
 #endif  // NET_BASE_DNSRR_RESOLVER_H_