Virtual destructors should have virtual keyword.

chrome/nacl/nacl_launcher_thread.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_NACL_NACL_THREAD_H_
 #define CHROME_NACL_NACL_THREAD_H_
 #pragma once
 
 #include "base/native_library.h"
 #include "chrome/common/nacl_types.h"
 #include "content/common/child_thread.h"
 
 // The NaClLauncherThread class represents a background thread where
 // NaCl app gets started.
 class NaClLauncherThread : public ChildThread {
  public:
   explicit NaClLauncherThread(bool debug);
-  ~NaClLauncherThread();
+  virtual ~NaClLauncherThread();
   // Returns the one NaCl thread.
   static NaClLauncherThread* current();
 
  private:
   virtual bool OnControlMessageReceived(const IPC::Message& msg);
   void OnStartSelLdr(std::vector<nacl::FileDescriptor> handles,
                      bool have_irt_file);
 
   int debug_enabled_;
 
   // TODO(gregoryd): do we need to override Cleanup as in PluginThread?
   DISALLOW_COPY_AND_ASSIGN(NaClLauncherThread);
 };
 
 #endif  // CHROME_NACL_NACL_THREAD_H_