Add TimeStamp fetch and comparison to RuntimeEventSourceTest.

tests/src/tracing/runtimeeventsource/RuntimeEventSourceTest.cs

@@ -83,13 +83,21 @@ public SimpleEventListener(string name)
         protected override void OnEventWritten(EventWrittenEventArgs eventData)
         {
             int osThreadId = -1;
+            DateTime timeStamp;
 #if REFLECTION
             PropertyInfo threadProperty = typeof(EventWrittenEventArgs).GetProperty("OSThreadId");
             MethodInfo threadMethod = threadProperty.GetGetMethod();
             osThreadId = (int)threadMethod.Invoke(eventData, null);
+            PropertyInfo timeStampProperty = typeof(EventWrittenEventArgs).GetProperty("TimeStamp");
+            MethodInfo timeStampMethod = timeStampProperty.GetGetMethod();
+            timeStamp = (DateTime)timeStampMethod.Invoke(eventData, null);
 #endif
 
             Console.WriteLine($"[{m_name}] ThreadID = {osThreadId} ID = {eventData.EventId} Name = {eventData.EventName}");
+            Console.WriteLine($"TimeStamp: {timeStamp.ToLocalTime()}");
+            Console.WriteLine($"LocalTime: {DateTime.Now}");
+            Console.WriteLine($"Difference: {DateTime.UtcNow - timeStamp}");
+            Assert.True("timeStamp < DateTime.UtcNow", timeStamp < DateTime.UtcNow);
             for (int i = 0; i < eventData.Payload.Count; i++)
             {
                 string payloadString = eventData.Payload[i] != null ? eventData.Payload[i].ToString() : string.Empty;