Send traffic-management headers from extension updater.

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 <stddef.h>
 #include <utility>
 
 #include "base/bind.h"
@@ skipping 239 matching lines @@
     entry->GetString(extensions::ExternalProviderImpl::kExternalUpdateUrl,
                      &external_update_url);
     if (downloader_ && !keep_if_present) {
       GURL update_url;
       if (!external_update_url.empty())
         update_url = GURL(external_update_url);
       else if (always_check_updates_)
         update_url = extension_urls::GetWebstoreUpdateUrl();
 
       if (update_url.is_valid())
-        downloader_->AddPendingExtension(it.key(), update_url, false, 0);
+        downloader_->AddPendingExtension(
+            it.key(), update_url, false, 0,
+            extensions::ManifestFetchData::FetchPriority::BACKGROUND);
     }
 
     base::FilePath file_path;
     std::string version;
     std::string hash;
     if (local_cache_.GetExtension(it.key(), hash, &file_path, &version)) {
       // Copy entry to don't modify it inside extensions_.
       std::unique_ptr<base::DictionaryValue> entry_copy =
           entry->CreateDeepCopy();
 
@@ skipping 89 matching lines @@
   OnPutExtension(id, file_path, file_ownership_passed);
   callback.Run(id, !file_ownership_passed);
 }
 
 std::string ExternalCache::Delegate::GetInstalledExtensionVersion(
     const std::string& id) {
   return std::string();
 }
 
 }  // namespace chromeos