Virtual destructors should have virtual keyword.

content/ppapi_plugin/ppapi_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 CONTENT_PPAPI_PLUGIN_PPAPI_THREAD_H_
 #define CONTENT_PPAPI_PLUGIN_PPAPI_THREAD_H_
 #pragma once
 
 #include "base/basictypes.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/process.h"
 #include "base/scoped_native_library.h"
 #include "build/build_config.h"
 #include "content/common/child_thread.h"
 #include "ppapi/c/pp_module.h"
 #include "ppapi/c/trusted/ppp_broker.h"
 #include "ppapi/proxy/plugin_dispatcher.h"
 
 class FilePath;
 class PpapiWebKitThread;
 
 namespace IPC {
 struct ChannelHandle;
 }
 
 class PpapiThread : public ChildThread,
                     public pp::proxy::PluginDispatcher::PluginDelegate {
  public:
   explicit PpapiThread(bool is_broker);
-  ~PpapiThread();
+  virtual ~PpapiThread();
 
  private:
   // ChildThread overrides.
   virtual bool OnMessageReceived(const IPC::Message& msg);
 
   // Dispatcher::Delegate implementation.
   virtual base::MessageLoopProxy* GetIPCMessageLoop();
   virtual base::WaitableEvent* GetShutdownEvent();
   virtual std::set<PP_Instance>* GetGloballySeenInstanceIDSet();
   virtual ppapi::WebKitForwarding* GetWebKitForwarding();
@@ skipping 36 matching lines @@
 
   // Lazily created by GetWebKitForwarding.
   scoped_ptr<ppapi::WebKitForwarding> webkit_forwarding_;
 
   scoped_ptr<PpapiWebKitThread> webkit_thread_;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(PpapiThread);
 };
 
 #endif  // CONTENT_PPAPI_PLUGIN_PPAPI_THREAD_H_