Don't forget to free the callbacks!

webkit/glue/resource_fetcher.cc

 // 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.
 
 #include "webkit/glue/resource_fetcher.h"
 
 #include "base/logging.h"
 #include "webkit/api/public/WebKit.h"
 #include "webkit/api/public/WebKitClient.h"
 #include "webkit/api/public/WebURLError.h"
@@ skipping 66 matching lines @@
   DCHECK(!completed_);
   DCHECK(data_length > 0);
 
   data_.append(data, data_length);
 }
 
 void ResourceFetcher::didFinishLoading(WebURLLoader* loader) {
   DCHECK(!completed_);
   completed_ = true;
 
-  if (callback_)
+  if (callback_.get()) {
     callback_->Run(response_, data_);
+    callback_.reset();
+  }
 }
 
 void ResourceFetcher::didFail(WebURLLoader* loader, const WebURLError& error) {
   DCHECK(!completed_);
   completed_ = true;
 
   // Go ahead and tell our delegate that we're done.
-  if (callback_)
+  if (callback_.get()) {
     callback_->Run(WebURLResponse(), std::string());
+    callback_.reset();
+  }
 }
 
 /////////////////////////////////////////////////////////////////////////////
 // A resource fetcher with a timeout
 
 ResourceFetcherWithTimeout::ResourceFetcherWithTimeout(
     const GURL& url, WebFrame* frame, int timeout_secs, Callback* c)
     : ResourceFetcher(url, frame, c) {
   timeout_timer_.Start(TimeDelta::FromSeconds(timeout_secs), this,
                        &ResourceFetcherWithTimeout::TimeoutFired);
 }
 
 void ResourceFetcherWithTimeout::TimeoutFired() {
   if (!completed_) {
     loader_->cancel();
     didFail(NULL, WebURLError());
   }
 }
 
 }  // namespace webkit_glue