Convert WaitableEvent::EventCallback to OnceCallback

chrome/browser/browsing_data/chrome_browsing_data_remover_delegate.cc

Index: chrome/browser/browsing_data/chrome_browsing_data_remover_delegate.cc
diff --git a/chrome/browser/browsing_data/chrome_browsing_data_remover_delegate.cc b/chrome/browser/browsing_data/chrome_browsing_data_remover_delegate.cc
index 0cf44b96ea2b9888c0925ba7443b340d75e71d27..6f644644859488911ff6cfd1ac6781757fc0cfb4 100644
--- a/chrome/browser/browsing_data/chrome_browsing_data_remover_delegate.cc
+++ b/chrome/browser/browsing_data/chrome_browsing_data_remover_delegate.cc
@@ -914,7 +914,7 @@ void ChromeBrowsingDataRemoverDelegate::RemoveEmbedderData(
       base::WaitableEventWatcher::EventCallback watcher_callback = base::Bind(
           &ChromeBrowsingDataRemoverDelegate::OnWaitableEventSignaled,
           weak_ptr_factory_.GetWeakPtr());
-      watcher_.StartWatching(event, watcher_callback);
+      watcher_.StartWatching(event, std::move(watcher_callback));
     } else {
       // TODO(msramek): Store filters from the currently executed task on the
       // object to avoid having to copy them to callback methods.