Manual refactor to enum-based WaitableEvent for remaining mac/ios files

ios/chrome/browser/browser_state/chrome_browser_state_impl.cc

Index: ios/chrome/browser/browser_state/chrome_browser_state_impl.cc
diff --git a/ios/chrome/browser/browser_state/chrome_browser_state_impl.cc b/ios/chrome/browser/browser_state/chrome_browser_state_impl.cc
index 015658e6ac211831ebc3d0ae3883c0c7e6fc3c02..9972343b98f92a7cc15e6fa9316b9fce66f4eec3 100644
--- a/ios/chrome/browser/browser_state/chrome_browser_state_impl.cc
+++ b/ios/chrome/browser/browser_state/chrome_browser_state_impl.cc
@@ -72,7 +72,9 @@ void BlockFileThreadOnDirectoryCreate(base::WaitableEvent* done_creating) {
 void CreateBrowserStateDirectory(
     base::SequencedTaskRunner* sequenced_task_runner,
     const base::FilePath& path) {
-  base::WaitableEvent* done_creating = new base::WaitableEvent(false, false);
+  base::WaitableEvent* done_creating =
+      new base::WaitableEvent(base::WaitableEvent::ResetPolicy::AUTOMATIC,
+                              base::WaitableEvent::InitialState::NOT_SIGNALED);
   sequenced_task_runner->PostTask(
       FROM_HERE, base::Bind(&CreateDirectoryAndSignal, path, done_creating));
   // Block the FILE thread until directory is created on I/O pool to make sure