Virtual destructors should have virtual keyword.

content/renderer/plugin_channel_host.h

 // Copyright (c) 2010 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_RENDERER_PLUGIN_CHANNEL_HOST_H_
 #define CONTENT_RENDERER_PLUGIN_CHANNEL_HOST_H_
 #pragma once
 
 #include "base/hash_tables.h"
 #include "content/plugin/plugin_channel_base.h"
@@ skipping 28 matching lines @@
 
   static void Broadcast(IPC::Message* message) {
     PluginChannelBase::Broadcast(message);
   }
 
   bool expecting_shutdown() { return expecting_shutdown_; }
 
  private:
   // Called on the render thread
   PluginChannelHost();
-  ~PluginChannelHost();
+  virtual ~PluginChannelHost();
 
   static PluginChannelBase* ClassFactory() { return new PluginChannelHost(); }
 
   virtual bool OnControlMessageReceived(const IPC::Message& message);
   void OnSetException(const std::string& message);
   void OnPluginShuttingDown(const IPC::Message& message);
 
   // Keep track of all the registered WebPluginDelegeProxies to
   // inform about OnChannelError
   typedef base::hash_map<int, IPC::Channel::Listener*> ProxyMap;
   ProxyMap proxies_;
 
   // An IPC MessageFilter that can be told to filter out all messages. This is
   // used when the JS debugger is attached in order to avoid browser hangs.
   scoped_refptr<IsListeningFilter> is_listening_filter_;
 
   // True if we are expecting the plugin process to go away - in which case,
   // don't treat it as a crash.
   bool expecting_shutdown_;
 
   DISALLOW_COPY_AND_ASSIGN(PluginChannelHost);
 };
 
 #endif  // CONTENT_RENDERER_PLUGIN_CHANNEL_HOST_H_