Virtual destructors should have virtual keyword.

content/plugin/webplugin_delegate_stub.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_PLUGIN_WEBPLUGIN_DELEGATE_STUB_H_
 #define CONTENT_PLUGIN_WEBPLUGIN_DELEGATE_STUB_H_
 #pragma once
 
 #include <string>
 #include <vector>
@@ skipping 37 matching lines @@
 
   // IPC::Message::Sender implementation:
   virtual bool Send(IPC::Message* msg);
 
   int instance_id() { return instance_id_; }
   WebPluginProxy* webplugin() { return webplugin_; }
 
  private:
   friend class base::RefCounted<WebPluginDelegateStub>;
 
-  ~WebPluginDelegateStub();
+  virtual ~WebPluginDelegateStub();
 
   // Message handlers for the WebPluginDelegate calls that are proxied from the
   // renderer over the IPC channel.
   void OnInit(const PluginMsg_Init_Params& params, bool* result);
   void OnWillSendRequest(int id, const GURL& url, int http_status_code);
   void OnDidReceiveResponse(const PluginMsg_DidReceiveResponseParams& params);
   void OnDidReceiveData(int id, const std::vector<char>& buffer,
                         int data_offset);
   void OnDidFinishLoading(int id);
   void OnDidFail(int id);
@@ skipping 51 matching lines @@
   // window handle which is used for subsequent communication back to the
   // browser.
   void OnSetFakeAcceleratedSurfaceWindowHandle(gfx::PluginWindowHandle window);
 #endif
 #endif
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(WebPluginDelegateStub);
 };
 
 #endif  // CONTENT_PLUGIN_WEBPLUGIN_DELEGATE_STUB_H_