Migrate WaitableEvent to enum-based constructor in ppapi/

ppapi/proxy/ppp_messaging_proxy_unittest.cc

Index: ppapi/proxy/ppp_messaging_proxy_unittest.cc
diff --git a/ppapi/proxy/ppp_messaging_proxy_unittest.cc b/ppapi/proxy/ppp_messaging_proxy_unittest.cc
index d1fa9b60fde77fbbdd59ee7dedb7c391125b6c79..703e43035e4a8c3e87701d5737778f82199c4892 100644
--- a/ppapi/proxy/ppp_messaging_proxy_unittest.cc
+++ b/ppapi/proxy/ppp_messaging_proxy_unittest.cc
@@ -25,7 +25,9 @@ namespace {
 // template magic.
 PP_Instance received_instance;
 PP_Var received_var;
-base::WaitableEvent handle_message_called(false, false);
+base::WaitableEvent handle_message_called(
+    base::WaitableEvent::ResetPolicy::AUTOMATIC,
+    base::WaitableEvent::InitialState::NOT_SIGNALED);
 
 void HandleMessage(PP_Instance instance, PP_Var message_data) {
   received_instance = instance;