Virtual destructors should have virtual keyword.

chrome/browser/net/chrome_net_log.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 CHROME_BROWSER_NET_CHROME_NET_LOG_H_
 #define CHROME_BROWSER_NET_CHROME_NET_LOG_H_
 #pragma once
 
 #include <vector>
 
@@ skipping 86 matching lines @@
     // AddObserver and RemoveObserver methods.
     ChromeNetLog* net_log_;
 
    private:
     friend class ChromeNetLog;
     LogLevel log_level_;
     DISALLOW_COPY_AND_ASSIGN(ThreadSafeObserver);
   };
 
   ChromeNetLog();
-  ~ChromeNetLog();
+  virtual ~ChromeNetLog();
 
   // NetLog implementation:
   virtual void AddEntry(EventType type,
                         const base::TimeTicks& time,
                         const Source& source,
                         EventPhase phase,
                         EventParameters* params);
   virtual uint32 NextID();
   virtual LogLevel GetLogLevel() const;
 
@@ skipping 42 matching lines @@
   scoped_ptr<LoadTimingObserver> load_timing_observer_;
   scoped_ptr<NetLogLogger> net_log_logger_;
 
   // |lock_| must be acquired whenever reading or writing to this.
   ObserverList<ThreadSafeObserver, true> observers_;
 
   DISALLOW_COPY_AND_ASSIGN(ChromeNetLog);
 };
 
 #endif  // CHROME_BROWSER_NET_CHROME_NET_LOG_H_