Migrate WaitableEvent to enum-based constructor in base/

base/message_loop/message_pump_libevent_unittest.cc

Index: base/message_loop/message_pump_libevent_unittest.cc
diff --git a/base/message_loop/message_pump_libevent_unittest.cc b/base/message_loop/message_pump_libevent_unittest.cc
index 81afa5e58c1e8178b65c1f04d97b273f00cc0128..6a5a1f36235786cba27857dadb23a18ce3da3e86 100644
--- a/base/message_loop/message_pump_libevent_unittest.cc
+++ b/base/message_loop/message_pump_libevent_unittest.cc
@@ -248,7 +248,8 @@ TEST_F(MessagePumpLibeventTest, QuitWatcher) {
   RunLoop run_loop;
   MessagePumpLibevent::FileDescriptorWatcher controller;
   QuitWatcher delegate(&controller, &run_loop);
-  WaitableEvent event(false /* manual_reset */, false /* initially_signaled */);
+  WaitableEvent event(WaitableEvent::ResetPolicy::AUTOMATIC,
+                      WaitableEvent::InitialState::NOT_SIGNALED);
   std::unique_ptr<WaitableEventWatcher> watcher(new WaitableEventWatcher);
 
   // Tell the pump to watch the pipe.