Virtual destructors should have virtual keyword.

chrome/browser/extensions/extension_history_api.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_BROWSER_EXTENSIONS_EXTENSION_HISTORY_API_H_
 #define CHROME_BROWSER_EXTENSIONS_EXTENSION_HISTORY_API_H_
 #pragma once
 
 #include <map>
 #include <string>
@@ skipping 54 matching lines @@
 
   bool GetUrlFromValue(Value* value, GURL* url);
   bool GetTimeFromValue(Value* value, base::Time* time);
 };
 
 // Base class for history funciton APIs which require async interaction with
 // chrome services and the extension thread.
 class HistoryFunctionWithCallback : public HistoryFunction {
  public:
   HistoryFunctionWithCallback();
-  ~HistoryFunctionWithCallback();
+  virtual ~HistoryFunctionWithCallback();
 
   // Return true if the async call was completed, false otherwise.
   virtual bool RunAsyncImpl() = 0;
 
   // Call this method to report the results of the async method to the caller.
   // This method calls Release().
   virtual void SendAsyncResponse();
 
   // Override HistoryFunction::RunImpl.
   virtual bool RunImpl();
@@ skipping 56 matching lines @@
 class DeleteRangeHistoryFunction : public HistoryFunctionWithCallback {
  public:
   virtual bool RunAsyncImpl();
   DECLARE_EXTENSION_FUNCTION_NAME("history.deleteRange");
 
   // Callback for the history service to acknowledge deletion.
   void DeleteComplete();
 };
 
 #endif  // CHROME_BROWSER_EXTENSIONS_EXTENSION_HISTORY_API_H_