Virtual destructors should have virtual keyword.

chrome/browser/icon_manager.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.
 //
 // Class for finding and caching Windows explorer icons. The IconManager
 // lives on the UI thread but performs icon extraction work on the file thread
 // to avoid blocking the UI thread with potentially expensive COM and disk
 // operations.
 //
 // Terminology
@@ skipping 42 matching lines @@
 #include "chrome/browser/icon_loader.h"
 #include "content/browser/cancelable_request.h"
 #include "ui/gfx/image.h"
 
 class FilePath;
 
 class IconManager : public IconLoader::Delegate,
                     public CancelableRequestProvider {
  public:
   IconManager();
-  ~IconManager();
+  virtual ~IconManager();
 
   // Synchronous call to examine the internal caches for the icon. Returns the
   // icon if we have already loaded it, NULL if we don't have it and must load
   // it via 'LoadIcon'. The returned bitmap is owned by the IconManager and must
   // not be free'd by the caller. If the caller needs to modify the icon, it
   // must make a copy and modify the copy.
   gfx::Image* LookupIcon(const FilePath& file_name,
                          IconLoader::IconSize size);
 
   typedef CancelableRequestProvider::Handle Handle;
@@ skipping 35 matching lines @@
 
   // Asynchronous requests that have not yet been completed.
   struct ClientRequest;
   typedef std::map<IconLoader*, ClientRequest> ClientRequests;
   ClientRequests requests_;
 
   DISALLOW_COPY_AND_ASSIGN(IconManager);
 };
 
 #endif  // CHROME_BROWSER_ICON_MANAGER_H_