Migrate WaitableEvent to enum-based constructor in base/

base/trace_event/trace_sampling_thread.cc

Index: base/trace_event/trace_sampling_thread.cc
diff --git a/base/trace_event/trace_sampling_thread.cc b/base/trace_event/trace_sampling_thread.cc
index a8d32d6ee2ab348421b00ab0aea05368e5bfd343..5a0d2f8a024e12f3a23fbc6673bba1bbaedb323a 100644
--- a/base/trace_event/trace_sampling_thread.cc
+++ b/base/trace_event/trace_sampling_thread.cc
@@ -25,7 +25,9 @@ class TraceBucketData {
 };
 
 TraceSamplingThread::TraceSamplingThread()
-    : thread_running_(false), waitable_event_for_testing_(false, false) {}
+    : thread_running_(false),
+      waitable_event_for_testing_(WaitableEvent::ResetPolicy::AUTOMATIC,
+                                  WaitableEvent::InitialState::NOT_SIGNALED) {}
 
 TraceSamplingThread::~TraceSamplingThread() {}