clang-tidy WaitableEvent refactor (ChromeOS side)

chrome/browser/chromeos/extensions/default_app_order.cc

Index: chrome/browser/chromeos/extensions/default_app_order.cc
diff --git a/chrome/browser/chromeos/extensions/default_app_order.cc b/chrome/browser/chromeos/extensions/default_app_order.cc
index ee118046e77f1fd1674c1cef009236450343eb97..eabdbe85fa28bc822806a2ac9ffaa21ce6493ac3 100644
--- a/chrome/browser/chromeos/extensions/default_app_order.cc
+++ b/chrome/browser/chromeos/extensions/default_app_order.cc
@@ -121,7 +121,8 @@ void GetDefault(std::vector<std::string>* app_ids) {
 const size_t kDefaultAppOrderCount = arraysize(kDefaultAppOrder);
 
 ExternalLoader::ExternalLoader(bool async)
-    : loaded_(true /* manual_rest */, false /* initially_signaled */) {
+    : loaded_(base::WaitableEvent::ResetPolicy::MANUAL,
+              base::WaitableEvent::InitialState::NOT_SIGNALED) {
   DCHECK(!loader_instance);
   loader_instance = this;