Use the new callback tracker and delete the old one

webkit/plugins/ppapi/ppb_file_system_impl.cc

 // 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.
 
 #include "webkit/plugins/ppapi/ppb_file_system_impl.h"
 
 #include "base/memory/ref_counted.h"
 #include "ppapi/c/pp_completion_callback.h"
 #include "ppapi/c/ppb_file_system.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebDocument.h"
@@ skipping 65 matching lines @@
       return PP_ERROR_FAILED;
   }
 
  PluginInstance* plugin_instance = ResourceHelper::GetPluginInstance(this);
   if (!plugin_instance)
     return PP_ERROR_FAILED;
 
   if (!plugin_instance->delegate()->OpenFileSystem(
           plugin_instance->container()->element().document().url(),
           file_system_type, expected_size,
-          new FileCallbacks(plugin_instance->module()->AsWeakPtr(),
-                            pp_resource(), callback, NULL,
+          new FileCallbacks(this, callback, NULL,
                             scoped_refptr<PPB_FileSystem_Impl>(this), NULL)))
     return PP_ERROR_FAILED;
   return PP_OK_COMPLETIONPENDING;
 }
 
 PP_FileSystemType PPB_FileSystem_Impl::GetType() {
   return type_;
 }
 
 }  // namespace ppapi
 }  // namespace webkit