Migrate WaitableEvent to enum-based constructor in sync/

sync/internal_api/syncapi_server_connection_manager_unittest.cc

Index: sync/internal_api/syncapi_server_connection_manager_unittest.cc
diff --git a/sync/internal_api/syncapi_server_connection_manager_unittest.cc b/sync/internal_api/syncapi_server_connection_manager_unittest.cc
index 9e67be8df9c71f7c11165ae82d5f06b433cb3239..aedc7c1a79ed935e6047516b16354bb4b052f159 100644
--- a/sync/internal_api/syncapi_server_connection_manager_unittest.cc
+++ b/sync/internal_api/syncapi_server_connection_manager_unittest.cc
@@ -24,7 +24,9 @@ using base::TimeDelta;
 
 class BlockingHttpPost : public HttpPostProviderInterface {
  public:
-  BlockingHttpPost() : wait_for_abort_(false, false) {}
+  BlockingHttpPost()
+      : wait_for_abort_(base::WaitableEvent::ResetPolicy::AUTOMATIC,
+                        base::WaitableEvent::InitialState::NOT_SIGNALED) {}
   ~BlockingHttpPost() override {}
 
   void SetExtraRequestHeaders(const char* headers) override {}