Virtual destructors should have virtual keyword.

webkit/appcache/appcache_disk_cache.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 WEBKIT_APPCACHE_APPCACHE_DISK_CACHE_H_
 #define WEBKIT_APPCACHE_APPCACHE_DISK_CACHE_H_
 
 #include <vector>
 
 #include "base/memory/scoped_ptr.h"
@@ skipping 39 matching lines @@
   class CreateBackendCallback
       : public net::CancelableCompletionCallback<AppCacheDiskCache> {
    public:
     typedef net::CancelableCompletionCallback<AppCacheDiskCache> BaseClass;
     CreateBackendCallback(AppCacheDiskCache* object,
                           void (AppCacheDiskCache::* method)(int))
         : BaseClass(object, method), backend_ptr_(NULL) {}
 
     disk_cache::Backend* backend_ptr_;  // Accessed directly.
    private:
-    ~CreateBackendCallback() {
+    virtual ~CreateBackendCallback() {
       delete backend_ptr_;
     }
   };
 
   enum PendingCallType {
     CREATE,
     OPEN,
     DOOM
   };
   struct PendingCall {
@@ skipping 23 matching lines @@
   net::CompletionCallback* init_callback_;
   scoped_refptr<CreateBackendCallback> create_backend_callback_;
   PendingCalls pending_calls_;
   scoped_ptr<disk_cache::Backend> disk_cache_;
 };
 
 }  // namespace appcache
 
 #endif  // WEBKIT_APPCACHE_APPCACHE_DISK_CACHE_H_