Move OS_WIN specific logic in MessagePumpDefault::Run into waitable_event_win.cc

base/synchronization/waitable_event_unittest.cc

Index: base/synchronization/waitable_event_unittest.cc
diff --git a/base/synchronization/waitable_event_unittest.cc b/base/synchronization/waitable_event_unittest.cc
index ac5c9f125584da09b4a829cf24f8a250e8f81ab8..545f7be440c95a976447b70c6073d5be0d4b4c9e 100644
--- a/base/synchronization/waitable_event_unittest.cc
+++ b/base/synchronization/waitable_event_unittest.cc
@@ -160,4 +160,15 @@ TEST(WaitableEventTest, MAYBE_TimedWait) {
   PlatformThread::Join(thread);
 }
 
+// Tests that a sub-ms TimedWait doesn't time out promptly.
+TEST(WaitableEventTest, SubMsTimedWait) {
+  WaitableEvent ev(WaitableEvent::ResetPolicy::AUTOMATIC,
+                   WaitableEvent::InitialState::NOT_SIGNALED);
+
+  TimeDelta delay = TimeDelta::FromMicroseconds(900);
+  TimeTicks start = TimeTicks::Now();
+  ev.TimedWait(delay);
+  EXPECT_GE(TimeTicks::Now() - start, delay);
+}
+
 }  // namespace base