Don't forget to free the callbacks!

webkit/glue/image_resource_fetcher.h

 // Copyright (c) 2006-2008 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_GLUE_IMAGE_RESOURCE_FETCHER_H_
 #define WEBKIT_GLUE_IMAGE_RESOURCE_FETCHER_H_
 
 #include "base/basictypes.h"
 #include "webkit/glue/resource_fetcher.h"
 
@@ skipping 21 matching lines @@
   const GURL& image_url() const { return image_url_; }
 
   // Unique identifier for the request.
   int id() const { return id_; }
 
  private:
   // ResourceFetcher::Callback. Decodes the image and invokes callback_.
   void OnURLFetchComplete(const WebKit::WebURLResponse& response,
                           const std::string& data);
 
-  Callback* callback_;
+  scoped_ptr<Callback> callback_;
 
   // Unique identifier for the request.
   const int id_;
 
   // URL of the image.
   const GURL image_url_;
 
   // The size of the image. This is only a hint that is used if the image
   // contains multiple sizes. A value of 0 results in using the first frame
   // of the image.
   const int image_size_;
 
   // Does the actual download.
   scoped_ptr<ResourceFetcher> fetcher_;
 
   DISALLOW_EVIL_CONSTRUCTORS(ImageResourceFetcher);
 };
 
 }  // namespace webkit_glue
 
 #endif  // WEBKIT_GLUE_IMAGE_RESOURCE_FETCHER_H_