Virtual destructors should have virtual keyword.

chrome/browser/file_select_helper.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_FILE_SELECT_HELPER_H_
 #define CHROME_BROWSER_FILE_SELECT_HELPER_H_
 #pragma once
 
 #include <map>
 #include <vector>
@@ skipping 11 matching lines @@
 
 
 // This class handles file-selection requests coming from WebUI elements
 // (via the ExtensionHost class). It implements both the initialisation
 // and listener functions for file-selection dialogs.
 class FileSelectHelper
     : public SelectFileDialog::Listener,
       public NotificationObserver {
  public:
   explicit FileSelectHelper(Profile* profile);
-  ~FileSelectHelper();
+  virtual ~FileSelectHelper();
 
   // Show the file chooser dialog.
   void RunFileChooser(RenderViewHost* render_view_host,
                       TabContents* tab_contents,
                       const ViewHostMsg_RunFileChooser_Params& params);
 
   // Enumerates all the files in directory.
   void EnumerateDirectory(int request_id,
                           RenderViewHost* render_view_host,
                           const FilePath& path);
 
  private:
   // Utility class which can listen for directory lister events and relay
   // them to the main object with the correct tracking id.
   class DirectoryListerDispatchDelegate
       : public net::DirectoryLister::DirectoryListerDelegate {
    public:
     DirectoryListerDispatchDelegate(FileSelectHelper* parent, int id)
         : parent_(parent),
           id_(id) {}
-    ~DirectoryListerDispatchDelegate() {}
+    virtual ~DirectoryListerDispatchDelegate() {}
     virtual void OnListFile(
         const net::DirectoryLister::DirectoryListerData& data) {
       parent_->OnListFile(id_, data);
     }
     virtual void OnListDone(int error) {
       parent_->OnListDone(id_, error);
     }
    private:
     // This FileSelectHelper owns this object.
     FileSelectHelper* parent_;
@@ skipping 52 matching lines @@
 
   // Registrar for notifications regarding our RenderViewHost.
   NotificationRegistrar notification_registrar_;
 
   DISALLOW_COPY_AND_ASSIGN(FileSelectHelper);
 };
 
 class FileSelectObserver : public TabContentsObserver {
  public:
   explicit FileSelectObserver(TabContents* tab_contents);
-  ~FileSelectObserver();
+  virtual ~FileSelectObserver();
 
  private:
   // TabContentsObserver overrides.
   virtual bool OnMessageReceived(const IPC::Message& message) OVERRIDE;
 
   // Called when a file selection is to be done.
   void OnRunFileChooser(const ViewHostMsg_RunFileChooser_Params& params);
 
   // Called when a direction enumeration is to be done.
   void OnEnumerateDirectory(int request_id, const FilePath& path);
 
   // FileSelectHelper, lazily created.
   scoped_ptr<FileSelectHelper> file_select_helper_;
 
   DISALLOW_COPY_AND_ASSIGN(FileSelectObserver);
 };
 
 #endif  // CHROME_BROWSER_FILE_SELECT_HELPER_H_