Make WaitableEventWatcher TaskScheduler-friendly.

base/synchronization/waitable_event_watcher_win.cc

Index: base/synchronization/waitable_event_watcher_win.cc
diff --git a/base/synchronization/waitable_event_watcher_win.cc b/base/synchronization/waitable_event_watcher_win.cc
index 6533539d14db8b4cc35e7348d82e78c724998b32..a3eb73b10e081cae2ab8f5d94a20ffd1d5a9226c 100644
--- a/base/synchronization/waitable_event_watcher_win.cc
+++ b/base/synchronization/waitable_event_watcher_win.cc
@@ -10,9 +10,7 @@
 
 namespace base {
 
-WaitableEventWatcher::WaitableEventWatcher()
-    : event_(NULL) {
-}
+WaitableEventWatcher::WaitableEventWatcher() = default;
 
 WaitableEventWatcher::~WaitableEventWatcher() {
 }
@@ -31,10 +29,6 @@ void WaitableEventWatcher::StopWatching() {
   watcher_.StopWatching();
 }
 
-WaitableEvent* WaitableEventWatcher::GetWatchedEvent() {
-  return event_;
-}
-
 void WaitableEventWatcher::OnObjectSignaled(HANDLE h) {
   WaitableEvent* event = event_;
   EventCallback callback = callback_;