Virtual destructors should have virtual keyword.

webkit/plugins/npapi/test/plugin_thread_async_call_test.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 WEBKIT_PLUGINS_NPAPI_TEST_PLUGIN_THREAD_ASYNC_CALL_TEST_H_
 #define WEBKIT_PLUGINS_NPAPI_TEST_PLUGIN_THREAD_ASYNC_CALL_TEST_H_
 
 #include "webkit/plugins/npapi/test/plugin_test.h"
 
 namespace base {
 class ShadowingAtExitManager;
 }
 
 namespace NPAPIClient {
 
 // This class tests scheduling and unscheduling of async callbacks using
 // NPN_PluginThreadAsyncCall.
 class PluginThreadAsyncCallTest : public PluginTest {
  public:
   PluginThreadAsyncCallTest(NPP id, NPNetscapeFuncs *host_functions);
-  ~PluginThreadAsyncCallTest();
+  virtual ~PluginThreadAsyncCallTest();
 
   virtual NPError New(uint16 mode, int16 argc, const char* argn[],
                       const char* argv[], NPSavedData* saved);
 
   virtual NPError Destroy();
 
   void AsyncCall();
   void OnCallSucceeded();
   void OnCallCompleted();
 
  private:
   // base::Thread needs one of these.
   base::ShadowingAtExitManager* at_exit_manager_;
 
   DISALLOW_COPY_AND_ASSIGN(PluginThreadAsyncCallTest);
 };
 
 }  // namespace NPAPIClient
 
 #endif  // WEBKIT_PLUGINS_NPAPI_TEST_PLUGIN_THREAD_ASYNC_CALL_TEST_H_