Migrate WaitableEvent to enum-based constructor in content/

Change automated with clang-tidy (details @ https://crbug.com/612843#c13)

BUG=612843

Review-Url: https://codereview.chromium.org/2026253003
Cr-Commit-Position: refs/heads/master@{#397386}
diff --git a/content/browser/appcache/appcache_response_unittest.cc b/content/browser/appcache/appcache_response_unittest.cc
index efb3818..9c279d3 100644
--- a/content/browser/appcache/appcache_response_unittest.cc
+++ b/content/browser/appcache/appcache_response_unittest.cc
@@ -81,7 +81,9 @@
 
   template <class Method>
   void RunTestOnIOThread(Method method) {
-    test_finished_event_ .reset(new base::WaitableEvent(false, false));
+    test_finished_event_.reset(new base::WaitableEvent(
+        base::WaitableEvent::ResetPolicy::AUTOMATIC,
+        base::WaitableEvent::InitialState::NOT_SIGNALED));
     io_thread_->task_runner()->PostTask(
         FROM_HERE, base::Bind(&AppCacheResponseTest::MethodWrapper<Method>,
                               base::Unretained(this), method));