ExtensionUpdater: Abstract ExtensionDownloader creation

chrome/browser/chromeos/extensions/external_cache.cc

 // Copyright (c) 2013 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 "chrome/browser/chromeos/extensions/external_cache.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/callback.h"
 #include "base/file_util.h"
@@ skipping 192 matching lines @@
     delegate_->OnExtensionListsUpdated(cached_extensions_.get());
 }
 
 void ExternalCache::CheckCache() {
   if (local_cache_.is_shutdown())
     return;
 
   // If request_context_ is missing we can't download anything.
   if (!downloader_ && request_context_) {
     downloader_.reset(
-        new extensions::ExtensionDownloader(this, request_context_, NULL));
+        new extensions::ExtensionDownloader(this, request_context_));
   }
 
   cached_extensions_->Clear();
   for (base::DictionaryValue::Iterator it(*extensions_.get());
        !it.IsAtEnd(); it.Advance()) {
     const base::DictionaryValue* entry = NULL;
     if (!it.value().GetAsDictionary(&entry)) {
       LOG(ERROR) << "ExternalCache found bad entry with type "
                  << it.value().GetType();
       continue;
@@ skipping 96 matching lines @@
     delegate_->OnExtensionLoadedInCache(id);
   UpdateExtensionLoader();
 }
 
 std::string ExternalCache::Delegate::GetInstalledExtensionVersion(
     const std::string& id) {
   return std::string();
 }
 
 }  // namespace chromeos