Migrate WaitableEvent to enum-based constructor in tools/

tools/gn/input_file_manager.cc

 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "tools/gn/input_file_manager.h"
 
 #include <utility>
 
 #include "base/bind.h"
 #include "base/stl_util.h"
@@ skipping 185 matching lines @@
           "The file \"" + file_name.value() + "\" was previously loaded\n"
           "asynchronously (via a deps rule) and now you're trying to load it "
           "synchronously.\nThis is a class 2 misdemeanor: a single input file "
           "must be loaded the same way\neach time to avoid blowing my tiny, "
           "tiny mind.");
       return nullptr;
     }
 
     if (!data->loaded) {
       // Wait for the already-pending sync load to complete.
-      if (!data->completion_event)
-        data->completion_event.reset(new base::WaitableEvent(false, false));
+      if (!data->completion_event) {
+        data->completion_event.reset(new base::WaitableEvent(
+            base::WaitableEvent::ResetPolicy::AUTOMATIC,
+            base::WaitableEvent::InitialState::NOT_SIGNALED));
+      }
       {
         base::AutoUnlock unlock(lock_);
         data->completion_event->Wait();
       }
       // If there were multiple waiters on the same event, we now need to wake
       // up the next one.
       data->completion_event->Signal();
     }
   }
 
@@ skipping 94 matching lines @@
 
   // Run pending invocations. Theoretically we could schedule each of these
   // separately to get some parallelism. But normally there will only be one
   // item in the list, so that's extra overhead and complexity for no gain.
   if (success) {
     for (const auto& cb : callbacks)
       cb.Run(unowned_root);
   }
   return success;
 }